Continuity: In the first few scenes of the movie, General Ross has the gold striping on his shoulder epaulet rank on the inside of his shoulder, which is the wrong position. Later in the movie, the rank is switched back to proper military regulation.
Factual errors: As Dr. Betty Ross emerges from the side of the crashed helicopter on the roof top, she is seen grabbing onto the barrel of the Gattling Gun. This would be impossible as the temperature of the barrels would to be too hot to touch after being just fired prior to the helicopter crashing.
Continuity: During the scene where Bruce is talking with the man who works at the Pizza place, Bruce's hair in the front alters in between shots, in one shot, his hair is against his forehead, in the next shot, it's combed to the side, in the next shot, it's against his forehead again.
Factual errors: UH-1 Huey helicopter seen early in the film has an "N" registration number. Only US civilian aircraft have "N" registration numbers, US Military aircraft do not.
Factual errors: When the box of drinks containing the contaminated bottle is packaged, it has 'Brasil / U.S.A' printed on the side to show its destination. However, while Brasil is depicted with its Portuguese spelling, the acronym for the United States of America in Portuguese is 'E.U.A.' for Estados Unidos da América, not 'U.S.A.'
Revealing mistakes: Major Blonsky is identified as being "on loan" from the British Army. He appears however to be wearing the rank and insignia of a US Army CAPTAIN who is Special Operations Qualified.
Errors in geography: The scenes at Culver supposedly take place in the United States (e.g., USPS mailboxes, etc.) yet the bicycle rack circles say "City of Toronto".
Continuity: In the scene where Bruce explains to Betty what can and can't be tracked, the wallet goes from closed to open in one shot. And the $20 bill goes from being neatly tucked in her wallet to crumpled on the bed.
Continuity: During the Brazil chase scene, the time of day appears to change from night to day and back to night again. When the soldiers first enter Bruce's home, it is night and Bruce is thought to be sleeping. However, when Bruce is running through the city, it is clearly daylight, only to turn into night again as he enters the factory.
Revealing mistakes: The Portuguese spoken by some actors acting as Brazilian characters (like Tough Guy Leader) is heavily broken, with ridiculous accents. The Portuguese words and dialog are clearly phonetically memorized. Obviously only Brazilian actors Débora Nascimento and Rickson Gracie speak a real Portuguese.
Factual errors: The actual color of the Brazilian Guaraná drink is amber (similar to beer color) not lemon-green as it is showed in the soda factory where Bruce Banner work. Probably the intention was an analogy to Hulk's green color.
Factual errors: Unlike gasoline, aircraft fuel does not ignite upon contact with flame; it has to be aerated to a fine mist and ignited by a higher temperature flame than an average fire produces. The fuel spilled by the crashed helicopter in the final battle scene would not ignite and explode as the movie depicted; in fact, it would have put out the flames like water.
Continuity: The Polar F5 heart rate monitor watch used by Bruce Banner requires a wireless chest sensor in order to monitor a heart rate. There are several scenes where the chest sensor is clearly not present, yet the watch shows his current heart rate.
Errors in geography: At the scene Banner comes to Mexico, the locality informed as being Chiapas, is in fact the Rio de Janeiro city (where many scenes were shot). At 30min 44second, an orange garbage can with the logo "Prefeitura do Rio" (Rio's City Hall) is seen backwards the seat where are two women. These garbage cans are common in Rio De Janeiro city. Moreover, about one minute later, Banner is shown sleeping next to a green large door in which can be seen Portuguese words (graffiti) like "paulista" (people born in São Paulo) and "Ja e?" (a slang used in Rio, that means "let's go?" or "are you in?".
Incorrectly regarded as goofs: Although General Ross and the soldiers are in the Army, they fly around in Air Force helicopters. As part of part of U.S. Special operations Command he would have access to USAF SOC equipment.
Revealing mistakes: The MH-53 that Ross chases Blonsky in is a painfully obvious CGI effect.
Factual errors: No self-respecting Lt. General (or any other type of General for that matter) would be caught dead without his cover in public like Ross and Greller are throughout the film.
Incorrectly regarded as goofs: When Bruce is delivering the pizza, he rides a bicycle through the campus. As he weaves through the crowd we hear a bicycle bell. There is no bell on the bike's handle bars. But the bicycle bell sound could be came from those other bikes around the scene.
Errors in geography: In the scene where Bruce is in Guatemala buying pants he speaks to the lady in Spanish asking for bigger pants, to which she replies "tenho sim". It translates to "yes I do", the only problem is that "tenho sim" is Portuguese, not Spanish.
Continuity: The General and Emil Blonsky are in the helicopter/equipment bay talking about super soldiers, where General tells Emil about Banner's work; The General sits in a dentist-like chair and the immediate background behind his head changes from gray boxes to bright yellow strapped boxes and other assorted pile of gray boxes.
Anachronisms: The camouflage pattern used by Ross' US Army soldiers is the BDU woodland pattern, which has long been replaced by the digital ACU pattern.
Incorrectly regarded as goofs: The heavy downpour after the army gunship crashed, later referenced in the news story, is actually seen off in the distance as it approaches. It is also supposedly a plug for the upcoming Thor movie.
Factual errors: Tim Roth's character is a Captain, but not only is it against Military policy to grow a beard, it would not be tolerated from an Officer. So both his and the General's facial hair are way below Military standards.
Errors made by characters (possibly deliberate errors by the filmmakers): When Bruce is searching the computer database from the University computer lab, his search for "B* BANNER" fails to find anything. This is not surprising, since the check box titled "Allow Wildcards" is not checked just above the search field, so the search is only looking for a B followed by a literal asterisk.
Factual errors: Tim Roth's character is supposedly an British officer seconded to (detached to) the U.S. Army. Foreign officers on detached duty to the American armed forces do not wear American uniforms as Roth's character does in one scene. Only duly enlisted or commissioned members of the U.S. armed forces who have taken an oath of allegiance to the U.S. are allowed to wear the U.S. uniform.
Continuity: At the tunnel entrance, when Betty says "Bruce, wake up", he's seen without a baseball cap that suddenly appears after, at most, a split-second cut to her.
Revealing mistakes: General Ross is out of uniform, twice. His three stars on the green service coat are positioned to the outside where they are required to be centered on the epaulet, and his rank epaulets on his light green shirt are being worn backwards. (The thin gold stripe is required to be positioned to the outside. This is an especially grievous error as the epaulets are tapered, making it obvious as to which way to wear them.)
Incorrectly regarded as goofs: All pulse monitoring watches, like the one that Bruce is shown wearing requires the large button below the display to be held down for the pulse to appear. Bruce is never touching the watch while it shows his pulse increasing. At best, it would only display the last pulse reading after he had (possibly) removed his finger. This would apply to some heart-rate watches but the Polar F5 uses a wireless sensor strapped around the chest. That watch does not need a finger pressed to it to check the heart rate and will update continuously in monitor mode while exercising.
Revealing mistakes: During the final battle, Abomination pins Hulk against the brick wall of a building. With the amount of strength both characters previously displayed, they would have torn through the wall like paper.
Revealing mistakes: When General Ross enters a four-digit pass code to enter the deep-freeze storage area, the light on the panel turns green just before he enters the last digit of the code.
Factual errors: In the opening scenes, the name plate on his desk, reads: General Ross. That's a four star rank. Ross is a Lt. General, a three star rank. The nameplate should read, Lt. Gen. Ross.
Incorrectly regarded as goofs: Shortly after becoming the Hulk in the factory scene, Ed Norton's trousers are full length, then in the next scene they are knee length shorts. However, it's not inconceivable when a six foot person (Bruce) grows to nine foot (Hulk) while adding huge muscle mass, trousers would appear to be shorts.
Errors in geography: After getting out of their car on their way to New York, Bruce and Betty pass a sign on a bridge that says "8km/h, no wake". Clearly this was shot in Canada, as U.S. uses miles not kilometers.
Errors in geography: In the scene of battle on NYC street 2 neon disc sign is clearly seen. This is the famous logo of the Sam the Record Man store located on Yonge street in Toronto.
Continuity: After the helicopter explodes on the Hulk, he is shown with several cuts that are clearly bleeding red colored blood. Later on in the film, when he receives a gouge in his chest from the Abomination, he starts bleeding green blood.