Revealing mistake: During the chariot race, where the contestants are riding towards the screen, tyre tracks from the camera vehicle are clearly visible imprinted in the sand.
Continuity mistake: Ben-Hur places his crown on a table when he visits the fallen Messala, but upon returning the table and crown are gone.
Revealing mistake: When one of the ships collides with the other, you can clearly see that the rowers being hit are dummies.
Factual error: Al-Tair and al-Deberan are the names of the Arab Sheikh's horses, and he states they're named after the stars. Those stars were given their names by Arabian astronomers, and calculated astronomy by the Arabs emerged during medieval Islam in the 7th and 8th century CE, 674 years after the plot of the movie takes place.
Continuity mistake: Ben Hur's horses change position. When the chariots are preparing for the race and at the starting line, the horse with the pink nose is third from the left, but at the end of the race, the pink-nosed horse is fourth from the right.
Continuity mistake: When Judah takes rest on his way to Jerusalem funny things happen with his headgear. First, when he lies down it suddenly disappears under his head. Then he falls asleep, and when Balthasar from Alexandria approaches him a little later and he quickly gets up there is nothing under his head and back.
Continuity mistake: At the very end, the scaffold that was used to erect the crosses vanishes between shots.
Factual error: When Messala is passing through Nazareth, he says they will be in Jerusalem by tomorrow night. Nazareth is approximately 90 miles from Jerusalem. It would take three days to cover that distance, not one.
Revealing mistake: When Stephen Boyd is showing off the spikes on his chariot wheel you can see welding beads along the projecting hub.
Continuity mistake: When the baskets are being loaded to be lowered into the Valley of the Lepers, someone loads two heads of lettuce onto a basket. Just as the basket is being lowered, someone else throws in three more heads. When the basket hits the bottom, there are only three heads of lettuce.
Deliberate mistake: During the chariot race, the chariots crash together but the arrangement of the horses make it impossible for them to actually collide. In some instances (particularly in an aerial shot as Ben Hur and Messala round the turn) it is obvious that they repositioned the shaft of the chariot to between the first and third horses instead of being in the centre between the second and third.
Continuity mistake: One of the first shots in the picture is a wide angle establishing shot showing a street scene in Jerusalem, with milling people, animals, etc. A tall figure in the background is slowly walking toward the camera. The figure is Charlton Heston, and the shot is an earlier segment of a shot used later in the movie when Ben-Hur is returning home from a trade expedition. Heston's costume is the same, but he's only clearly recognizable in the second sequence. Since the two scenes are set 33 years apart, perhaps the earlier figure is Ben-Hur's father.
Continuity mistake: During the race, when Ben Hur is about to defeat Messala, his opponent's wheel disintegrates. However, as the chariot flips over, we see a complete wheel on both sides.
Factual error: When Judah is being led to the galleys after Jesus give him some water you see hills in the background, and a highway is going through them.
Continuity mistake: In the parade of chariots before the race, the riders are shown circling the track once before making their way to the starting line. As they emerge from the stables, the horses and chariots leave very noticeable tracks on the ground so you can trace their progress around the track. The riders head down the right side of the track (from the perspective of the stables) then make the wide turn to head down the backstretch, and then make the wide turn back onto the right side of the track where they started. The film then cuts to a wide shot of the riders heading back down the right side of the track for the second time, but the track ahead of them and all the way down the backstretch is now clean of any tracks. It's clear this shot comes from when the riders first emerged from the stables. The riders then stop on the starting line on the backstretch, which means they were either transported to the other side of the track without making a third turn, or they did 1 lap around the track in the space of 1 and a half laps.
Factual error: The actors and stunt drivers use only two reins to control the four horses that pull each chariot in the race. However, charioteers in ancient Rome used separate harnesses with two reins controlling each horse. In a race such as the one depicted in the movie, where four horses draw the chariot (two-horse races were common, as well), a real charioteer from the era would be holding eight reins.
Factual error: In the movie, Pontius Pilate is appointed to be governor of Judea around AD 32 (Judah is enslaved in AD 28, spends 3 years as a slave and then at least one year with Arrius before he meets Pilate, who is still not appointed). In reality, Pilate was the governor of Judea from AD 26-36.
Continuity mistake: Right before the chariot race, Sheik Ilderim is on Judah's left side, pointing out the spikes on Messala's wheels. There's a shot of the wheels and then back to Judah, where the Sheik is now on Judah's right side. Judah holds the Sheik's forearm as the fanfare starts. Then a long shot, showing the Sheik, now on Judah's left side again, and Judah removing his hand from the Sheik's forearm.
Factual error: The galley during the battle scene is rowed by slaves. Romans during this time period didn't use slaves to row their galleys. Rowers had to be able fight. If not, the Romans would be outnumbered 200 to 30 when they boarded the pirate ship as the pirates rowers would be able to fight.