Alice's new costume was designed by Milla Jovovich's clothing line, Jovovich-Hawk.

For the crow attack scene, only two crows were used for the entire sequence. The rest of the crows were entered with special effects.

The nightmares of Alice indicate that she has a mild psychic connection to her clones, since some of their memories are transferred into her subconscious. This element becomes important for the sequels.

Ali Larter was cast largely on the strength of her performance in the first two Final Destination movies.

The White Queen is never called specifically by name in the entire film, although Alice alludes to it by saying "I knew your sister" (the Red Queen from Resident Evil (2002)). This continues the tradition of the first film to reference characters and places from Alice in Wonderland, where the Red and White Queen are sisters.

The film was not screened for critics, most likely due to the overwhelmingly-negative reviews from critics for the first two films, especially from Roger Ebert, that had a hate list of the other Resident Evil movies.

Milla Jovovich wasn't interested in doing a third Resident Evil film due to her disappointment with Resident Evil: Apocalypse (2004). However she changed her mind after reading the script and some changes were made to it.

The idea for the two Kukri knives were from Milla Jovovich's fight trainer from Resident Evil: Apocalypse (2004), Ron Balicki.

A conscious decision was made early on to make this the bloodiest of the Resident Evil films.

Claire Redfield's role in the movie is quite different from in the games. She leads a convoy of survivors across the dead desert and commands several army-type people, suggesting some sort of military background. In the games, she has a university degree and a basic combat & firearms training from her brother Chris Redfield, and she is on a mission to find him.

Temperatures would often be excess of 130 degrees Fahrenheit on the Mexican locations. Various members of the crew frequently would have to be treated for dehydration.

The early draft of the script reveals K-Mart's real name: it is Elizabeth Jane Case. The novelization gives her birth name as Dahlia Julia Mancini, which explains her unease with it a bit better.

The trademark double spiral-shaped injections (representing D.N.A.) now have two liquids instead of one. The one spiral contains the blue liquid (the T-virus) and the other one contains the green liquid (the anti virus). The mixture is supposedly capable of bestowing the regenerative features of the T-virus but without succumbing to the atrocious side effects - mutation into an undead.

The original conception was that the storyline of this film would take place eight years after the events of Resident Evil: Apocalypse (2004). The filmmakers ultimately decided to shorten the time gap between the two films. According to some trailers and the film's official website, the story in the Nevada desert unfolds five years after the apocalypse in Raccoon City. Since the first two films take place in 2002 (evidenced by the newspaper visible at the end of the first film) Resident Evil Extinction is placed chronologically in 2007 coinciding with the film's release year.

The Blu-Ray release was the first Blu-ray movie that offered the 'picture in picture' feature.

The film's working title was Resident Evil: Afterlife, a title later granted to the fourth film in the franchise.

Domesticating the Zombie in the beginning of this film is clearly a reference to George A. Romero's Day of the Dead (1985) when "Bub" did virtually the same thing with an older phone.

In the Tokyo scene the sign next to 'Tokyo Metro' reads 'Zatoichi Square.' This is a nod to the fictional Japanese film and television character.

The film was originally intended to be filmed in the Australian Outback but was changed to Mexico.

The only film in the series to feature the character of the White Queen. No explanation had been offered for her absence in the rest of the series until the novelization for Resident Evil: The Final Chapter (2016), which states that she and the Red Queen are actually the same form of A.I. and not distinct.

The crows sitting on power lines and attacking in large numbers pays homage to Alfred Hitchcock's movie The Birds (1963).

There is no dialogue at all for the first 5 minutes of the film.

This is the second movie Linden Ashby collaborated with Paul W.S. Anderson; the other being Mortal Kombat (1995).

Starting with this Resident Evil movie, there are no more VHS releases.

At the beginning in the pit of dead Alice clones, none of them have been killed by the laser corridor trap.

Charlie Clouser was a last minute addition to the crew when the film's original composer unexpectedly dropped out.

The bonus material of the DVD contained a sneak preview of the first ever CGI Resident Evil movie, Resident Evil: Degeneration (2008). The CGI Resident Evil movies take place within the continuity of the Resident Evil video games, and have nothing to do with the live-action film franchise.

Milla Jovovich was pregnant with daughter and actress Ever Anderson during the premiere of this film in September, showing up to the red carpet with a prominent belly bump, and would give birth two months later in November. Ever Anderson would later have a role in the last sequel, Resident Evil: The Final Chapter (2016).

Costume Designer Joseph A. Porro worked on another movie based on a video game; Super Mario Bros.

Ashanti's first horror film.

There is a bonus audio clip following the rolling end credits.  It's Alice saying "you're just another asshole."

When the first clone dies after being shot by the spinning minigun in the test area, three figures in hazmat suits appear. When the middle figure takes off his mask to reveal Dr Isaacs, the camera crew is visible in the figure to the left of screen's mask.

The name of the terrifying mutation that Dr. Isaacs morphs into during the final sequence is never mentioned in the film, but people who have played the video games will recognize it as the Tyrant, the final boss in Resident Evil (1996) and the remake Resident Evil (2002). In fact, 'T-virus' stands for Tyrant virus in the games, as it gave rise to the monster with the characteristic external heart and the long claw on one hand. In the games, the claw cannot extend into tentacles; that is a hallmark of the Nemesis monster from Resident Evil 3: Nemesis (1999), but technical limitations prevented this from being realized in the previous adaptation, Resident Evil: Apocalypse (2004).

A deleted scene revealed that the zombie that was being studied was taken from a group of zombies that were roaming the desert. This zombie was apparently a Nashville Predators fan based upon the jersey he was wearing while captured.

No mention is made of Jill Valentine (Sienna Guillory) from the previous movie, Resident Evil: Apocalypse (2004). Guillory was offered the chance to reprise her role, but she had to turn it down due to scheduling conflicts with Eragon (2006), so the character was then written out of this sequel. She returned to the series as Jill in Resident Evil: Afterlife (2010) during the beginning of the end credits.

No mention is made of Angela Ashford (Sophie Vavasseur) who was rescued in the previous movie, Resident Evil: Apocalypse (2004). The initial script explained that shortly after the events of the second film, Angela was killed in an attack by Umbrella soldiers. While this was left out of the film, the novelization explains that Alice unintentionally killed her while under Umbrella's control. This would actually explain Alice's motivation to keep her distance from other survivors and stay out of reach of Umbrella's satellites more clearly.

Claire Redfield in the video games is on a prolonged search for her brother Chris. When the main plot of the film was planned, the original purpose of the trip to Alaska would be the reunion of Claire with her brother, since in the fourth game, Resident Evil - Code: Veronica (2000), they also finally meet up in a cold area (Antarctica). However, the Chris Redfield subplot was scrapped and the voyage to Alaska rewritten as a simple quest for a safe haven; Chris would appear in the next film, Resident Evil: Afterlife (2010).

There are 86 dead Alice clones filling up the trench at the start of the film.

The opening scene which recreates a sequence from the first film was scripted to be longer. Apart from finding the picture of the married couple , Alice would discover the rest of the clues seen in the first film, namely the hand written note or the drawer containing the weapons. Then she would enter the Red Queen's laser chamber. For pacing reasons the scene that appears in the finished film was trimmed down. It is noteworthy that after Alice sees the picture and hears a gust of wind, she simply looks at the statue. This is the only clue that the scene is just a simulation and not an exact copy of the first Resident Evil film. The original Alice asked "Hello" after she turned to the hall with the statue.

The original script implied that the reason for the global T-virus outbreak is that rats spread the infection. Apparently, the fact that these rodents live mostly underground helped them survive. This seems to reference the game series, where not the T- but the G-virus causes the viral outbreak in Raccoon City in Resident Evil 2 (1998); because the G-virus was accidentally spilled in the sewers, rats contracted it and spread it over the surface. Although this subplot was discarded, there is still a shot of rats dwelling in the sewers of Tokyo in the final scene of the film.

This is the first sequel that does not begin with the phrase "My name is Alice" for the opening narration states. The second sequel to do this would be Resident Evil: The Final Chapter (2016).

First appearance of Albert Wesker in the live-action Resident Evil films, who is a prominent antagonist in the game series from the first installment. It is also the only film in which the character is played by Jason O'Mara; Shawn Roberts took over the role for the last three movies, as O'Mara was unavailable to reprise his role. Although the difference in appearance between the actors is not that obvious as Wesker always wears his trademark sunglasses (even indoors), it can be explained by Wesker's near-constant genetic experimentation on himself.

Right around the crow attack scene there is a reference to Alice escaping from the Detroit facility. The Umbrella Corporation has facilities in every major city. Therefore, although Raccoon City looks like the real-world Detroit, in the world of the movie.

Contrary to popular belief the chronology for the third film is definite. Although trailers and the official website reveal that the story is set five years after the Raccoon City incident, the viewer does not have to rely on promotional material. The time period that has passed by since the beginning of the global infection is actually referenced in the film itself. When the convoy enters a decrepit Las Vegas they observe that it is covered by desert sand. Alice's lines draw attention to the fact that for 5 years there was no one left to clean up the city.

Dr. Isaacs spends all his time killing Alice clones and experimenting with the anti-virus, ironically at the end, he gets killed by Alice clones and the anti-virus.

At least one draft of the constantly changing script, dated June 2006, included a lot more monsters that were very similar to the Hunters (human/lizard hybrids) and Chimeras (human/insect hybrids) from the original video games.

Betty was originally supposed to survive until the end of the film in early drafts of the script, being the pilot who would fly away K-Mart, Claire, and the rest of the survivors to safety.

Mistakes

While Carlos is crawling under the truck his pistol's slide is forward, however when he tries to fire and we hear clicking, the slide is locked back indicating it is empty.

The opening scene in which Alice is naked in the shower shows her with no makeup. Yet, upon wearing the red dress she is wearing red lipstick. Then, in subsequent shots she is wearing no lipstick again.

When Alice approaches the trailer containing the super zombies, she has to get right next to it and listen carefully to realize there's anything inside. In the second movie it was shown that she had the ability to sense the presence of the T-virus, so she should have been alerted already.

The man that is thrown off the flamethrower and killed by the infected birds walks past Claire and the others when they discuss journeying to Alaska.

During the crow scene when the flamethrower is about to incinerate Carlos, the woman he is holding has her hand on his shoulder. When we cut to Alice in the next shot we can see the woman's hand slide down off of Carlos' shoulder and then reappear there in the next shot.

When crow attacks and the bus hits the pole, the pole breaks and falls down. In the next shot the pole is still half-intact, stuck to the bus.

Towards the end when Alice enters the Umbrella HQ and releases a clone of herself from the water/orb, the clone then dies. She is shown laying on the ground with her left hand covering only her left breast, with her elbow resting on the floor. In the next shot, from above, her arm is covering both and her elbow is no longer resting on the ground.

When Alice shoots the Stevie zombie through the head with an arrow, there is blood splatter on the truck after he is hit. After checking the pumps, Alice looks at him a second time and the blood splatter has vanished.

During the Vegas scene, the laptop in the Umbrella tent is locked on to Alice, yet there's a display box containing Africa in the lower left corner. There would be no logical reason for the Umbrella operatives to keep a look out on Africa when they're busy with Nevada.

About 3 minutes in, a laser defense mechanism slices off part of Alice's right boot. But moments later, during the same escape attempt, the boot appears to be intact.

Alice uses Sony ICF-SW12 Shortwave World Band Receiver Travel Radio at the beginning of a movie on her bike. This radio lacks scanner function and frequency coverage to receive mobile bands (CB/UHF/VHF). This means the only way for her to catch KLKB broadcast would be driving with one hand on the radio constantly turning tuning dial. She wouldn't be unable to hear convoy broadcast call at all.

When the convoy arrives in Las Vegas, the welcome sign says 'welcome to fantastic Las Vegas' but it should say 'welcome to fabulous Las Vegas'

When the bus gets attacked by the crows Ashanti's character Nurse Betty has blood and dirt on her face. But after she locks the back door and she shoots the crows she is clean and there is no blood or dirt on her, then in the next shot when she dies she is bloody again.

When the zombies are coming out of the large container, there are tons of them coming out of it but there's no way they could have all fit into the container in the first place.

In the last moments of the film when the camera pans out showing the many clones of Alice. The footage of the awoken clone in the bottom left can be seen reaching the end of the recording and then played in reverse to fill a few extra seconds.

At the start of the final scene in Tokyo, there are rats in the street. As the camera descends through the street, one of the rats actually goes in front of the ground revealing that the street is actually a cut-away set.

When Claire takes off in the helicopter she uses the cyclic stick and not the collective. Only the collective can be used to take off vertically.

During the scene in which Tokyo appears, there are several Japanese signs that just have random Japanese ideograms completely irrelevant to what should be there.

In the scenes in the pit with Alice and the zombie dogs, there are numerous shots where the dogs can be seen to still have furry, non-zombified tails.

When Alice comes across the empty gas station she aims her cross bow at the attendant zombie "Stevie" using a basic reflex sight on the bow, yet in the scene it shows that she has managed to magnify all the way up to his chest revealing his name. The sight used on the crossbow does not have anywhere near that amount of magnification.

When Carlos is saying goodbye to everyone and Claire is looking at him, you can clearly see traffic moving on the road in the background.

The women all have freshly shaved armpits while fighting an ongoing battle with zombies.

When Carlos is in the big rig lighting up his joint, the camera pulls back and you can clearly see that one of the zombies reaching in for him only has makeup just past his wrist where you can then see normal human skin between that and the sleeve of his clothing.

After the Alice clone is killed at the beginning, her body is shown being dumped into a pit with the other dead clones. Even though Dr. Isaacs has been killing the clones for weeks, none of the dead bodies show any decomposition, nor have any of them desiccated (dried out) in the desert heat.

When Alice walks through the dunes, just before the crow's attack, the cameraman filming her is visible in her glasses.

When Carlos and Alice reunite, Carlos mentions Detroit as the city in which they last saw each other. That location, Resident Evil: Apocalypse (the previous film) takes place in the fictional Raccoon City. However, Detroit is used for the exterior, establishing shots for Raccoon City in the Resident Evil films.

While all of the men look understandably worse for wear in this post-apocalyptic world, all of the women are sporting full faces of perfect makeup, clean untangled hair, and shaved underarms. There is no plausible way these women could look so good and clean given the state of the world.

After the characters arrive in Las Vegas, they park right next to the Paris Casino's Eiffel Tower and the Venetian Casino. In reality, The Venetian is one mile up Las Vegas Blvd (The Strip).

At the end of the movie, all survivors go to Umbrella HQ to get the helicopter. In fact it's very risky to bring everyone. Bringing noncombat personnel to that region risks the operation since they could have been killed or their presence decreases effectiveness of the heroes since they also should over watch the civilians. Since helicopter is a highly maneuverable vehicle it would be wiser to leave those civilians at a safe distance, go and get the helicopter and come and pick them up.

L.J. is bitten and infected at the beginning of the film and doesn't reanimate until a day and a half later, despite the fact that other infected victims have reanimated in much shorter time-spans. Alice even told Peyton in the previous film that he won't last more than 2 hours before reanimating into a zombie, and she would know this for certain as a former employee of Umbrella.

Alice's opening narration states that the T-Virus is slowly killing the earth by drying up bodies of water and turning forests into deserts. This setup doesn't even last the entire film, as the epilogue shows Wesker's Umbrella facility in Tokyo with vegetation and precipitation, completely contradicting Alice's opening narration.