Cat Stevens appears in a brief, uncredited role during Ruth Gordon's second appearance in the film. He is the bearded gentleman wearing a hat at and a full coat at a graveside service. His profile can be seen a few times as he looks at displeasure at Ruth Gordon trying to grab Burt Cort's attention during the service.
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.)
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.
Maude's picture frames are empty. In Colin Higgins's book, Harold asks why she removed the photographs (the scene was not used in the movie). Maude tells him they mocked her by their images remaining sharp even as her memories were fading, implying that she is suffering from Alzheimer's or a similar form of dementia.
Harold and Maude (1971) played for a total of 1,957 showings from mid-1972 until June 1974 at the Westgate Theater in Edina, Minnesota. Ruth Gordon appeared for the first anniversary celebration and both Gordon and Cort showed up for the second anniversary.
When considering the role of Harold, Bud Cort asked the opinion of director Robert Altman, his mentor. Altman cautioned that rising star Cort might find himself forever typecast. For this reason, Cort turned down the role of Billy Bibbit in One Flew Over the Cuckoo's Nest (1975).
Henry Dieckoff, who appeared as Mrs. Chasen's butler, was the actual butler of Rose Court Mansion in Hillsborough, California, south of San Francisco, which served as the setting for the Chasen mansion.
Most of the Cat Stevens songs heard in the film were taken from his albums Mona Bone Jakone or Tea for the Tillerman. He wrote the opening song, "Don't Be Shy", and "If You Want to Sing Out, Sing Out" especially for the film.
Flamboyant eighties pop star Boy George is a big fan of this movie. When he met Bud Cort on the set of Electric Dreams (1984), his first words to Cort were, "So you're the bloke who kept killing himself!"
On Tom Skerritt's credit as "M. Borman": "Skerritt's small role in the film, as an authoritarian motorcycle policeman, came about by accident when a previously cast actor broke his leg. Skerritt's film credit reads M. Borman, a reference to prominent Nazi official Martin Bormann, whose post-World War II whereabouts were still unknown. 'I said one day that he probably came out to Oakland and became a motorcycle cop, and so that's the way they put it in.'" Detroit Free Press, April 20, 2014, "Detroit native Tom Skerritt comes home Tuesday to reflect on his life, Hollywood times"
Two of Cat Steven's very popular songs from the film were not included on the "Harold and Maude" soundtrack album. "Don't Be Shy" and "If You Want To Sing Out, Sing Out" were not released on any album till 1989. They can be found on "Footsteps In The Dark: Greatest Hits Vol 2."
The trivia items below may give away important plot points.
The hearse Harold originally drives is a 1959 Cadillac Superior 3-way model that is one of the most sought after hearses among collectors today but at the time was considered nothing more than an undesirable used car which was purchased for a few hundred dollars. The Jaguar hearse was really destroyed at the end and no replica exists because they only constructed one version for filming.
While watching a sunset with Harold, Maude sees a flock of seagulls and refers to Dreyfus. Alfred Dreyfus (1859-1935), a Jewish officer in the French army, was wrongly convicted of treason in 1894, and sentenced to life in solitary confinement on Devil's Island (a penal colony off the coast of French Guiana). He was pardoned five years later, and ultimately exonerated when the evidence against him was proved false. The incident is seen by most historians as a revelation and indictment of French antisemitism, and its implications for French Jews still reverberate in France. The Dreyfus conversation coincides with Harold seeing Maude's concentration camp tattoo for the first time, which juxtaposes two of the most infamous instances of institutionalized European antisemitism of the nineteenth and twentieth centuries and strongly implies that Maude had been a Jewish concentration camp prisoner during World War II.
The Holocaust Encyclopedia resource on the website for the United States Holocaust Memorial Museum in Washington, D.C., says that tattoos of serial numbers were given only (and specifically) to prisoners at the Auschwitz complex of concentration camps (which included Auschwitz I [Main Camp], Auschwitz II [Auschwitz-Birkenau], and Auschwitz III [Monowitz and the subcamps]) who had been selected for work. Prisoners at other Nazi concentration camps were not tattooed; neither were prisoners at Auschwitz who were selected for immediate extermination instead of a work detail. The purpose of the tattoo was for the Nazis to have a system by which they could identify and catalog the bodies of the slave-laborer prisoners after their deaths.
It is believed that the film The Night Digger (1971) inspired both Colin Higgins and Hal Ashby in applying some of ideas of the film The Night Digger into this film. For example, both films have where a vehicle fall from the cliff. Both films show romantic relationship between an older woman and a young man. The Night Digger (1971) was released seven months prior to Harold and Maude (1971).