Stanley Kubrick was a big admirer of this film. He would often recite lines from the film to cast and crew on his films and he once invited Steve Martin over so they could play chess.
Because of a gas shortage, Steve Martin and Carl Reiner carpooled to the set every day. Reiner recalled, "Every day, we came up with at least one or two new jokes on the way to work."
The part where Navin licks Marie's face during their first date was completely improvised. Bernadette Peters' reaction was genuine.
Steve Martin adapted several bits of his standup act to fit within the film, such as a monologue in which he emotionally exits a scene, remarking "I don't need anything," but nevertheless picking up each object he passes on his way out.
Bill Murray filmed a cameo that was deleted. On the Saturday, December 15th, 1979 broadcast of Saturday Night Live (1975), Murray jokingly reviewed The Jerk (1979), saying: "I was in the movie but cut out of it. That doesn't influence my opinion. The movie is a dog. There's something missing. I don't know who it is, I can't say."