Brooks portrays a novelist who moves back home with his mother after his second divorce, hoping to determine why all his relationships with women were unsuccessful. Mother was Reynolds's first major film role in over 20 years. The film earned positive reviews and was Brooks's most financially successful film as a director.
John Henderson (Albert Brooks) is a successful science fiction writer who is finalizing his second divorce. He is perplexed by the issues he has with women, realizing that his wives and girlfriends all didn't support or encourage him. John decides to initiate an experiment that will help him understand what went wrong in his relationships: he moves back in with his widowed mother Beatrice (Debbie Reynolds), occupying the same bedroom he had as a child. His sports agent brother Jeff thinks John is oversensitive to their mother's criticism, while John believes that their mother favors Jeff.
Their relationship is characterized by constant bickering and power struggles; both are perfectionists strongly committed to their respective points of view. John believes she's overly critical of him, while Beatrice contends that he blames her unfairly for his personal failings. A rare bright spot in their relationship appears appears when she takes an interest in his word processor and impresses John with her fast, flawless typing. Beatrice seems surprised by John's interest in her life and is reluctant to 'go into all that.'
When Beatrice cancels her plans to travel to visit her son Jeff, Jeff has a meltdown and an argument with his wife over his need to keep in constant contact with his mother. She tells him that he may needs to evaluate his relationship with his mother just as much as John. John and Beatrice go to the zoo, where they finally reach some common ground. When they return home Jeff is waiting; so upset by the aborted visit, he came all the way up to try to talk Beatrice into visiting for the weekend. All three argue and Jeff leaves alone, John satisfied that Jeff's the "sickie" and that he's "pretty darn healthy to begin with."
Beatrice tells John that she has a friend who comes through San Francisco every few weeks and stays over a few days, but while John is there this visit will be just for one day but that she needs to see him. John is surprised that she would call someone she is intimate with not important, but she dismisses it, saying they "just have sex occasionally." John meets Charles, who knows a lot about John because, as he tells John, Beatrice brags about him when he's not around. They head off to have dinner; in the car they discuss the evening, with Beatrice refusing to have anything more than dinner because of her son's visit, even though the idea of more seems to excite Charles.
While alone at the house, John discovers a box of novel and short story manuscripts that his mother wrote in her youth. He learns she was a skilled writer who went to college on a scholarship, only to have her talent discouraged by her husband and the prevailing social expectations that mothers should not have careers outside the home. John realizes now that his mother's passive aggression towards him and not Jeff stems from the fact that Jeff's business career was never a reminder of her unfulfilled ambitions. Beatrice admits that John's observations are correct, leading to a warm reconciliation.
The film ends with John meeting a single female fan of his novels, and Beatrice beginning to write a story based on John's moving in with her. John meets a woman and a relationship begins to spark.
Brooks wanted a famous actress from the 1950s to play the role of Mother, and originally offered the role to retired actresses Nancy Reagan and Doris Day. Day turned down the offer; Reagan loved the script, and considered coming out of retirement for her first acting role in more than 40 years, but decided instead to stay home and care for her husband, Ronald Reagan, who was suffering from Alzheimer's disease. Brooks then asked his good friend Carrie Fisher if she could send the script to her mother, Debbie Reynolds, who accepted the part. Reynolds hadn't had a starring role since the late 1960s.
Mother was filmed on location in and around the Sausalito, Greenbrae, and Tiburon areas, with additional shooting in San Francisco. The exterior of Beatrice's house and street was shot in Studio City.
Mother received mostly positive reviews from critics, and holds a 90% rating on review aggregator Rotten Tomatoes, based on 41 reviews. Roger Ebert of The Chicago Sun-Times gave Mother 3.5 stars out of a possible 4, writing that while the premise seemed like the setup for a cheap sitcom, Brooks "is much too smart to settle for the obvious gags and payoffs. [...] The dialogue in "Mother" is written so carefully that some lines carry two or three nuances." The audience laughter wasn't a reaction to obvious punchlines, wrote Ebert, "but the laughter of recognition, of insight, even sometimes of squirmy discomfort, as the truths hit close to home".
Mother remains Brooks' highest-grossing directorial effort to date, earning $19.1 million at the box office.
Mother won the most awards of the films which Brooks has directed. Brooks and co-writer Monica Johnson won the New York Film Critics Circle Award and the National Society of Film Critics Award for Best Screenplay. Debbie Reynolds won a Golden Satellite Award for Best Performance by an Actress in a Supporting Role in a Motion Picture - Comedy or Musical, and was nominated for the Golden Globe Award for Best Actress - Motion Picture Musical or Comedy.