Frumpy, overweight wife and mother Ruth Patchett desperately attempts to please her accountant husband Bob, who is trying to boost his business. After Bob meets narcissistic romance novelist Mary Fisher at a party, they begin an affair. Ruth, aware of the affair, confronts Bob while his parents are visiting, and Bob leaves her. Angry, Ruth vows revenge on him and Mary.

Ruth lists Bob's assets, representing his home, his family, his career and his freedom, planning to cross off each one after destroying it. With Bob away at Mary's and the kids at school, she procures Mary's financial records and overloads the electricity of the house, destroying the house in a massive explosion. She leaves the kids with Mary and Bob and tells him that she will not be returning.

Bob's second asset, his family, slowly deteriorates, as Mary's selfish refusal to learn how to be a mother causes tension in her relationship with Bob and begins to interfere with her ability to write her newest romance novel. Mary's new novel is loosely based on her romance with Bob, but her publisher Paula considers it strange and off-putting as there is a chapter about laundry.

Ruth takes a job at a nursing home under the pseudonym Vesta Rose, where she befriends Francine, Mary's foul-mouthed, estranged mother, and arranges for her to return to Mary's life at an inopportune moment. She also meets Hooper, a nurse who has worked for the nursing home for 22 years and put aside her earnings for a considerable life savings. Though Ruth horrifies Hooper by secretly switching the senior citizens' sedatives and mundane routines for vitamin and caffeine pills and enriching activities, she gains Hooper's trust by introducing her to desserts.

After Ruth is fired from the home for dumping a urine filled bed pan on Francine's bed to frame her as a bed-wetter and prevent her return, she and Hooper form a partnership and start an employment agency for downtrodden women who have been rejected by society and need a second chance. The agency is successful, and the women Ruth has helped assist her in getting revenge on Bob. Olivia, an attractive but ditsy young blonde, applies to the agency, and she is hired as Bob's secretary where he starts sleeping with her at the office. This causes Mary to become lonely and desperate at night, which makes Bob rebuff her advances. When Olivia proclaims her love for Bob, he immediately dumps and fires her. Olivia reveals to Ruth that Bob is a fraudster who cons money out of his clients by skimming interest off their accounts, then transferring it to his offshore account in Switzerland.

As Mary is being interviewed for a puff piece by People, her mother reveals embarrassing secrets about her that effectively destroy her career. Olivia and Ruth hack Bob's computer to conduct a gigantic embezzlement, then report this to the IRS. Ruth also mails pictures of Bob bedding Olivia to Mary. Intent on regaining control of her life, Mary forces her mother and Bob's children to behave, then throws an elegant party with her friends. All goes well until state troopers appear with a warrant for Bob's arrest. Bob's lawyer bribes a corrupt male judge to ensure a favorable verdict, and unknowingly informs Mary that Bob has been stealing from her account as well, causing her to leave Bob and sell her mansion. A woman who gained employment as a court clerk via Ruth's agency repays Ruth by reassigning Bob's case to an unbiased female judge. Bob is convicted of embezzlement and sentenced to 18 months in prison, thus destroying his fourth and final asset: his freedom. As Bob is taken away, he realizes that his greed, selfishness, and infidelity towards Ruth have left him with nothing.

Sixteen months later, Ruth and her children visit a greatly reformed Bob, who is now on considerably more amicable terms with Ruth following their divorce and looking forward to catching up with his children after his upcoming release from prison. Ruth concludes that although people can change as Bob has, not everyone does so. Mary has revived her career by becoming a more mainstream author and is at a book signing about a new tell-all book, where she signs a book for Ruth but does not recognize her. Next in line after Ruth is a man whom Mary clearly tries to flirt with, indicating she has not completely changed her ways. The film ends with Ruth smiling as she walks down a busy street in Manhattan, accompanied by women from her firm.

• Meryl Streep as Mary Fisher
• Roseanne Barr as Ruth Patchett
• Ed Begley Jr. as Bob Patchett
• Linda Hunt as Hooper
• Sylvia Miles as Mrs. Fisher
• Elisebeth Peters as Nicolette Patchett
• Bryan Larkin as Andy Patchett
• A Martinez as Garcia
• Maria Pitillo as Olivia Honey
• Mary Louise Wilson as Mrs. Trumper
• Susan Willis as Ute
• Jack Gilpin as Larry
• Robin Leach as himself
• Nitchie Barrett as Bob's secretary
• June Gable as a realtor
• Sally Jessy Raphael as herself
• Doris Belack as Paula
• Lori Tan Chinn as Vesta Rose woman
• Rosanna Carter as Judge Brown

The film score for She-Devil was composed by Howard Shore. A soundtrack album was released on November 15, 1989 by Mercury Records.^[3] Shore's score was later released in a limited edition of 1,000 copies by Music Box Records.^[4]

On the review aggregator website Rotten Tomatoes, 48% of 25 critics' reviews are positive, with an average rating of 4.8/10.^[5] Metacritic, which uses a weighted average, assigned the film a score of 45 out of 100, based on 21 critics, indicating "mixed or average" reviews.^[6]

Streep was nominated for a Golden Globe Award for Best Actress – Motion Picture Comedy or Musical.^[7]

The film was shot on location at 161 Cliff Road, 11777 Port Jefferson, New York. The house was demolished in 2017; the 30-bedroom estate belonged to Bulgarian operetta singer and actress Nadya Nozharova, also known as Countess Nadya de Navarro Farber, who died in 2014. The home was built in 1870 and was almost 19,000 sq ft (1,800 m²). The countess lived in the home for over 40 years.^[8]

• Sathi Leelavathi (1995) — Tamil remake of this film

• She-Devil at IMDb  
• She-Devil at the TCM Movie Database
• She-Devil at Rotten Tomatoes
• She-Devil at the American Film Institute Catalog