Continuity mistake: After they leave the French plantation Chief Phillips maneuvers the boat through some thick fog and says, "I said I can't see a thing captain I'm stopping this boat, I ain't riskin' no more lives". When he says this line he's looking directly at Captain Willard but in the next shot his head is turned as he looks over towards his right. (02:20:15)????
Factual error: The date on the top of Chef's letter from Eva says, "Sept" with the year conveniently whited out. If the letter was written in September of 1969 she couldn't have known about Manson who wasn't arrested until December 3, 1969. This also dates the movie as taking place sometime in 1970. (01:50:50)????
Factual error: Captain Willard recalls back to lunch at General Corman's and we hear Harrison Ford's voice say as he points to a map, "Now he's crossed into Cambodia". The town he's pointing at (Ban Me Thout) and the one above it are in the Central Highlands in the middle of Vietnam and not crossover points anywhere near Cambodia. (01:18:20)????
Continuity mistake: As they begin to break out of the fog bank Chef says, "watch it over here, chief, got a stump". Here he's helping Chief Phillips steer the boat with a long pole that he places back on the floor of the boat after the uses it. You can see that it's not hanging over the right side of the boat behind Chief Philips but at the beginning of the arrow attack it's back extending out over the side. Then a few shots later as Captain Willard runs to the back of the boat to stop Chef from firing it's gone completely. (02:20:55)????