Plot hole: Wouldn't Taylor have suspected he was still on Earth, seeing as all the apes were speaking English?
Continuity mistake: When Julius arrives to escape Taylor from his cell, he gives the guard a note who has a cigar in his mouth. When Julius tackles the guard, the size of the cigar differs between shots. (01:18:50)
Revealing mistake: If you look closely at the back of the head of both Zira and Dr. Zaius, you can see the actor's real hair.
Continuity mistake: The American flag on the raft moves from shot to shot. That can't happen, because the raft was tethered to the spaceship while Taylor was throwing the supplies down. (00:10:15)
Revealing mistake: As Lucius tackles the guard and yells "Grab him!" to Taylor, Lucius then strikes the guard over the head, knocking him unconscious. When Lucius begins pushing the guard over to Taylor's cell, you can see the guard is already unconscious before he gets struck. (01:18:45)
Continuity mistake: When Taylor is trying to describe where he came from to Zira and Cornelius, he has Cornelius hold up a map. Cornelius holds the left side and Taylor holds up the right. As Zira says "You fell into the water here?", the map is slanted to the side. In the next shot, Taylor suddenly isn't holding the right side of the map and the map is more levelled out. (00:48:20)
Other mistake: Taylor believes he is on a planet 300 light-years from earth for most of the movie. However, after spending months there, he would have seen the moon at night a number of times, letting him know where he really was before seeing the Statue of Liberty.
Suggested correction: Not necessarily; any astronaut knows that many, many planets have moons, so Taylor could have easily thought that it was simply an odd coincidence that the "other" planet's moon closely resembled Earth's moon.
Continuity mistake: Towards the end when Taylor is shaving, they show a shot of him when he is nearly finished; only a small dab of the shave cream left on his chin. Cut to a shot of Lucius and Cornelius looking at him from behind and his face is completely lathered once again.
Continuity mistake: When Taylor and Nova approach the Statue of Liberty, there is a slow panning shot looking down on them from behind the statue's crown. All of the spikes on the crown are completely straight when seen from this angle. When the camera angle changes and we're looking up at the statue, there is a spike on the left side of the crown bent outward. The bend starts a little more than half-way up the spike; it would have been visible in the shot from behind.
Revealing mistake: When Taylor approaches Miss Liberty, there should be horse tracks in the sand extending to the end of the frame. About 1/3 of the frame shows smooth sand preceding some horse tracks.
Continuity mistake: At the beach when Cornelius reads the scroll his fingers swap between being under the scrolls to being on top.
Visible crew/equipment: After Taylor exits the museum he is whipped by an ape on a horse. Taylor/Charlton Heston is replaced by a noticeable stunt. (00:58:57)
Continuity mistake: When Taylor discovers Stewart's corpse his hand is on his chest but a shot later it's by his side.
Audio problem: After Taylor's been hit Dr. Galen says "he's lost a lot of blood", but his mouth is not moving.
Continuity mistake: While during the trial Honorius says Zira and Galen experimented on Taylor his right-hand swaps between being by his side or resting on the chair.
Revealing mistake: During the trial Honorius walks around the room and stops to deliver his words. Watch his feet and you'll notice a dark spot right where his feet are, which serves as the marker.
Continuity mistake: When Julius beats Taylor he protects himself. The position of his hand changes between shots.
Visible crew/equipment: When Zira locks Nova in Taylor's cell watch the left iron bar and you'll see the shadow of the camera approaching.
Continuity mistake: Zira visits the cages and asks Taylor if it still hurts. Taylor holds the iron bars with both hands parallel to each other. A shot later his right hand is positioned higher.
Continuity mistake: After Zaius warns Taylor not to go to the Forbidden Zone, Taylor turns the horse to face Cornelius. In the closeup after Zaius tells Taylor "You may not like what you find", he turns the horse around again.
