The interior of Larry's apartment was the only set built for this film.
Woody Allen appears in an uncredited cameo as Jake, an old bearded love-poem seller, in the film's first bar scene. Director Paul Mazursky would direct Allen as an actor again, this time credited, in the later feature film 'Scenes from a Mall' (1991).
Director Paul Mazursky starred in Fear and Desire (1952) by Stanley Kubrick. The Christopher Walken character, Robert Fulmer, is based on Howard Sackler, the writer of Fear and Desire (1952).
Debut theatrical feature film of actor Bill Murray who appears uncredited as Nick Kessel. He has a couple scenes as a crowd extra.
Woody Allen: Uncredited, the New York actor-writer-director, heavily made-up in make-up with a thick beard making him virtually unrecognizable, as Jake, an old love-poem seller, seen in the film's first bar scene early in the movie.