Harold Chasen is a 20-year-old boy, solitary and friendless by choice, who drives a hearse and is obsessed with death: he ties to attract his mother’s attention staging his own fake suicides. The exasperated woman, a wealthy socialite who is controlling, snobbish and apparently incapable of affection. decides to send him to a psychiatrist and find him a girlfriend through a computer dating service, completely unaware of Harold’s true unhappiness
During a therapy session, Harold explains that he enjoys attending funerals. It is at one of these funerals that he meets Maude, a 79-year-old lady who shares his hobby of attending funerals. She offers him some liquorice and suggests that the deceased, who was 80, died at the perfect age. She then tells Harold they will be “great friends” and steals the minister’s car.
Unlike Harold, Maude is obsessed with life and her philosophy of life is to take it as it is, live each day to its fullest and try something new every day, without getting caught up in traps such as worry over humiliation
The boy is fascinated by her peculiar outlook on life, so joyful and carefree in contrast with his morbidity. Little by little she opens him to the wonders and possibilities of life, to the sensual pleasures of music and art and the general anarchy of living for the moment and doing whatever one pleases.
While his mother is determined, against his wishes, to get him to settle down with someone she considers appropriate. he horrifies each of his appointed dates . She also tries to interest him in military service with the help of uncle Victor, an elderly general, who is convinced all of Harold’s problems could be solved if he joins the army. However the boy manages to deter his uncle by staging a scene in which Maude poses as a pacifist protester and is seemingly murdered by him out of militaristic fanaticism. Therefore the shocked Victor, convinced Harold killed the protestor, stops talking about his enlisting.
Fascinated by Maude’s creativity and her insistence on experiencing something new each day, Harold shares with her his favourite activities: watching building demolitions and picnicking at a metal junkyard. When she explains that she likes to watch things grow and picks a tall solitary sunflower as her preferred flower, Harold, in turn, chooses a ground cover daisy, saying that all daisies are alike, but Maude shows him little differences between them. She tells him that all humans are special; the problem is when they allow themselves to be treated all the same.
On another occasion Maude removes a tree on the point of being suffocated by the city’s smog and is going to transplant it to the forest, when she is stopped by the police but speeds off during the officer’s interrogation.
Back at Maude’s home, Harold explains the reason of his fake suicides; When he was at boarding school, during a chemistry lab experiment he accidentally caused an explosion, which led police to assume his death. Harold returned home just in time to see the police report to Mrs. Chasen that her son had died in the explosion. Seeing his mother faint and appreciating her attention Harold decided to continue dying, because he ”enjoyed being dead.”
As they become closer, their friendship blossoms into a romance: Maude is showing Harold how to truly live, and the boy falls in love with her. and announces that he will marry her. Horrified by their age difference, his mother sends him to see Victor, the psychiatrist, and a priest, who suggests that the idea of Harold “commingling” his “firm” body with the elderly woman is perverse
On Maude’s 80th birthday, Harold fills her room with paper sunflowers and plans to propose to her. Maude tells Harold that she “couldn’t imagine a lovelier farewell.” Confused, he questions Maude as to her meaning and she reveals that she has taken enough sleeping tablets to kill her by midnight and wishes him farewell restating her firm belief that eighty is the proper age to die.
Harold calls for an ambulance and, on the way to the hospital, as he professes his love to her, Maude looks on approvingly and tells Harold to “go love some more.” She has shown him how to live well, and now how to die well.
In the final sequence, Harold’s car is seen going off a seaside cliff but after the crash, the final shot reveals Harold, standing calmly on the cliff’s edge, picking out on the banjo that Maude gave him the notes to Cat Stevens’ “If You Want to Sing Out, Sing Out”. He is celebrating life as Maude would have wanted.