The film first introduces us to Harold, an alienated teenaged boy from a wealthy family who lives in a large mansion with his dominating mother. Harold stages realistic mock suicides. This has evidently been going on for so long that his mother takes no notice, other than when Harold causes a particular mess with his fake blood. For amusement, Harold attends funerals of people he doesn't know. At these he repeatedly sees Maude, a 79 year-old woman who befriends him. Maude is very much his opposite: energetic, impulsive, and light-hearted. The two form an unlikely friendship, then romance.
The film features Bud Cort as Harold and Ruth Gordon as Maude; the soundtrack is by Cat Stevens, containing many songs which he composed specifically for the movie and which were unavailable for several decades on vinyl or cassette (they were later released on the compact disc Footsteps in the Dark).