Were bow and arrow used in Vietnam war?

Answer 1

Yes, the North Vietnamese were using gigantic crossbows to take out helicopters. The Vietnamese guerrilla unit(s) also used crossbows in Vietnam, as they were silent, accurate and deadly, and allowed one to pick off the last guy in line without alerting the rest, maybe taking out three or four before anyone was the wiser.

Answer 2

Possibly by guerilla forces, but not established armies (the last confirmed kill with bow and arrow was at Dunkirk 1940)

Answer 3

Yes, the American special forces used them to take out sentries because of the silence and accuracy a crossbow offers to a trained user.