Continuity mistake: When Bond is flying over China and landing on the sea by Scaramanga's island, you can see that his plane has two floats - one on either wing. But in the shot where he is heading for the beach, it is clearly seen that the left float has gone! (01:28:40 - 01:30:55)
Continuity mistake: The people inside the elevator disappear in the wide angle. (01:57:21 - 01:57:51)
Continuity mistake: The small plane's pilot identifies the aircraft as 232Z. But in the exterior shots, the aircraft's identification is N9750Y. (00:35:00)
Other mistake: In the original version of the film there's a mistake in the opening credits where Colin Blakely's name is misspelled as Colin Blankey.
Revealing mistake: When Gittes visits the orange grove and crashes into the tree, you can see that a steel plate has been placed around the tree to protect it.
Continuity mistake: When Stewart arrives at Denise's place, a book suddenly appears on top of the books on the second shelf.
Visible crew/equipment: When the hearse drives in reverse, two filming crew members plus the camera are reflected on the glass.
Other mistake: When Hyman Roth's assassin runs at the airport, he is turning around with one (of two) bullet holes already in his jacket before the sound of any gunfire. (03:10:50)
Continuity mistake: After the general is killed, there's a close-up on the figurines. Two are broken with just the feet left, the third, the rightmost, at the waist. When the second victim was murdered, we saw the killer break just its head off, the statue to the right of the halved one. The following shot shows the statues in that order, with the addition of third broken one in rightmost position. (00:34:15 - 00:42:15)