Factual error: Captain Willard narrates to himself, "I am beyond their timid lying, morality, and so I am beyond caring" as we see a downed helicopter burning in a tree. The main rotors are detached and would not be sitting on top of the helicopter had it actually crashed and not just been placed there. In an actual helicopter crash the rotors fly off. (01:22:10)????
Continuity mistake: After speaking to Bill Graham in the tent Captain Willard comes back and tells the guys, "I negotiated two barrels of fuel for a couple of hours with the bunnies". As he walks back to the boat the hills in the distance can't be seen because of the rain but in the next shot when Chief Phillips comes over to talk to him the hills can be seen. (01:26:25)????
Continuity mistake: Captain Willard says, "the army tried one last time to bring him back into the fold" and we see a close-up of General Corman again sitting at lunch with the captain from earlier in the movie. This was not shot at the same time because the general's shirt is different. Look closely at his name, the collar covers everything except the first two letters whereas earlier in the movie, for the entire scene his name was showing and could be read. (01:18:10)????
Continuity mistake: As Colonel Kurtz opens up the steel doors to the room where Captain Willard is being held we see thick black smoke engulfing the entire area behind the colonel. They cut away to the captain for few seconds then back to the colonel as he stands in the doorway, this time with no smoke at all behind him. (02:49:05)????
Continuity mistake: As Captain Willard approaches Lieutenant Colby there is a woman standing in the crowd to the right of him. The next time we see him a few seconds later everyone in the shot is standing in the same spot except the woman is gone and a man wearing a green beret appears in her place. (02:32:40)????