Trivia

Michael Ontkean replaced John Heard. The latter was originally cast as Willie but was allegedly fired during filming.

When the trio are tripping on acid in the movie theatre, they're watching Más allá del valle de las muñecas (1970).

Willie and Phil, the two central characters of this movie's title, meet in the film when they come out of a screening of Jules y Jim (1962), the film of which this movie is based.

The title roles played by Michael Ontkean and Ray Sharkey were once intended for Woody Allen and Al Pacino.

This movie is an American remake of Francois Truffaut's French film Jules y Jim (1962) which had been made about just under twenty years earlier.

Natalie Wood: As Herself.

Paul Mazursky: Uncredited, as the voice of the film's narrator.