Continuity mistake: When Commodus is choking Aurelius we see Aurelius placing his hands on Commodus' shoulders. When it cuts back to a frontal shot of Commodus the hands are gone. (00:34:20)
Continuity mistake: During the scene in which Maximus battles one-on-one with Tigris of Gaul (the gladiator that returned from retirement) in the Coliseum, Maximus is ordered to kill the Tigris. As he refuses and throws the axe down, the left side of Maximus' neck is completely covered with blood. When Commodus enters to speak with Maximus, there is only the slightest trace of blood on his neck, which now also seems to be completely dry. (01:43:35 - 01:44:30)
Factual error: Women were not allowed to be mixed with men. Only Vestales could stay where men were. Women could see the games just from the last ring-level of the Colosseum.
Revealing mistake: When the chariot crashes in to the gladiators, we can see the shield in which the chariot crashes in to. It's not shaped like the other shields which are shaped in a perfect bow. This shield is rectangular shaped most likely to balance better on what ever is supporting it when the chariot runs over it making the chariot tip over. (01:30:00)
Continuity mistake: When Maximus grabs some earth before the final fight, you can see blood from the wound already trickle through his shirt, but when he picks up the sword it is magically gone. (02:13:55)
Revealing mistake: After the first gladiator fight when Maximus and Juba have finished off the last gladiator, it cuts to a wide shot of the arena. The camera moves to the left, if you look at the back row you can see two men with modern day T-shirts talking. (00:55:45)
Character mistake: When Maximus is talking to Marcus Aerelius, he mentions that his wife has black hair. But in the scenes where we see her, she actually has brown hair. (00:24:40)
Factual error: Several men, most notably Marcus Aurelius, are long-haired (for male standards) in the movie. In Roman fashion, men were expected to use their hair short. Male long hair was seen in a very bad light, especially for an emperor.
Factual error: There are several points in the film that show horses with saddles and stirrups. Pretty odd as the stirrup didn't arrive in Europe from China until the 3rd or 4th Century at the earliest.
Factual error: In the arena, Maximus tells Commodus and the Roman spectators that he is "general of the Felix legions." The problem is, there was just one Felix legion, namely Legio IV Flavia Felix. (01:27:35)
Factual error: The snake with red-yellow-brown skin you see in a night-shot in Rome is a Pueblan Milk Snake (Lampropeltis triangulum campbelli) from Mexico, also found in southern Texas. Not quite right for Rome... (02:04:15)
Continuity mistake: When Commodus tells his nephew Lucius about Roman history, the hairdo of Lucius changes a few times during the scene. (02:03:00)
Continuity mistake: When Lucilla says "Did you know, I still remember you in my prayers?" she looks up at Maximus with a serious face. When it cuts she is smiling. (00:28:35)
Audio problem: When Maximus is eating with Juba and Hagen, just before he fights Tigris of Gaul, listen to the background noise very closely as the men talk. There's lots of chatter and stray noises, but amid the sounds you can hear someone yelling urgently: "Warren, Warren... Warren...radio." This may be the sounds of a crew member telling another regarding a radio. (01:36:30)
Continuity mistake: In the battle scene between Maximus and Tigris, not only does the visor flip up and down (see above), but when Tigris falls down with his visor up, you can see that his face isn't marked. But when Maximus again unmasks Tigris, it's bloody with a giant scrape across the face. (01:42:35)
Continuity mistake: At the beginning when Maximus is walking past the rows of soldiers look closely and you can see some of the same soldiers twice. (00:03:15)
Revealing mistake: After Hagen has been shot and stabbed, as he falls dying to the ground, the pad the arrows are attached to on his back is quite noticeable under his shirt. (02:07:15)
Continuity mistake: During the battle of Carthage, Maximus rides past another man standing on the ground and throws a spear into his chest. The man clutches the spear with his right hand as he falls backwards, but when it cuts to him hitting the ground both his hands are out to the side and the spear has suddenly disappeared. (01:21:50)
Continuity mistake: During the first gladiator fight in the Colosseum, Maximus picks up the arrow from the ground. His hand is covered in blood, but in the second camera shot, no blood at all, and then in the third shot, you can see the blood again. (01:26:25)
Factual error: As the Gladiators are being led into the Colosseum for the first time, an elephant is led across the background. Although the Romans used elephants in the arena, they used African elephants, and the one we see is an Asian elephant.
Suggested correction: This movie is not based upon facts. Many element were fictionalized. This is just example of fictionalized things.