- Billing Displacement: Glaucus (Maude's sculptor friend) was written and filmed as a much bigger part, but most of it got trimmed for pacing purposes. Still, Cyril Cusack received fourth billing.
- Breakaway Pop Hit: Averted with "Don't Be Shy" and "If You Want to Sing Out, Sing Out." Two of Cat Stevens' contributions to the soundtrack, they were never released as singles and didn't appear on an album until over a decade after the movie came out.
- Breakthrough Hit: For Hal Ashby.
- Deleted Scene:
- There is a deleted scene in which Maude paints smiles on the statues in the church. A still from this scene can be found on one of the original lobby cards, and it is described in detail in the book-adaptation. In the movie, the priest from the graveside service at the cemetery refers to a similar incident when he asks Maude, "Are you also the one who painted the saint?" (Referring to the Saint on the dashboard of his VW Bug which Maude steals.)
- There is a deleted scene in which Mrs. Chasen talks with Harold's dummy, mistaking him for her son. It is described in detail in the book-adaptation.
- Executive Veto: Hal Ashby intended to film a scene of Harold and Maude making love, but Paramount dismissed this idea.
- Throw It In:
- The scenes in which Harold turns to look at the camera after successfully scaring off his first date, and when he does "the finger" behind his mother's back after she sees the Jaguar turned into a Hearse, were not in the script, rather, they were improvised by Bud Cort.
- When Maude and Harold steal the police officer's motorcycle, Bud Cort accidentally hit himself in the head with the shovel, but just kept going for the sake of the shot.
- What Could Have Been:
- An early draft of the script took place in Los Angeles.
- Hal Ashby felt that Maude should ideally be European and his list of possible actresses included Peggy Ashcroft, Agatha Christie and Lotte Lenya. Bud Cort wanted Greta Garbo.
- For Harold, in addition to Bud Cort, Ashby considered all promising unknowns Bob Balaban and Richard Dreyfuss. Also on his list was Elton John, whom Ashby had seen live and hoped would also do the music.
Trivia / Harold and Maude