Judith Rossner, who died yesterday at 70, was the author of 10 novels, including the best-selling “Looking For Mr. Goodbar,” published in 1975.

“Goodbar,” based on an actual New York City murder, tells the story of a Catholic-school teacher who seeks fulfillment by cruising singles’ bars for tawdry sex by night.

Appearing at a moment when doubts were setting in about the benefits of 1960s-style sexual license, and packed with jarringly explicit sex scenes culminating in the main character’s murder, the book proved spectacularly successful. It sold more than 4 million copies and became a 1977 movie of the same title.

The success allowed Rossner to quit her day job to concentrate on writing, but she never again reached the heights of sales or critical acclaim that “Goodbar” achieved.

Rossner grew up in the Bronx. Her father, an alcoholic, was a textile merchant. Her mother was a schoolteacher who doted on her young daughter and encouraged her, from an extremely young age, to become a writer.

“I was dictating to my mother when I was 5,” she told Publishers Weekly. “I was raised to be a writer, to be accomplished.”

Rossner’s mother committed suicide many years later, and alcoholic fathers and suicidal mothers were to become common themes of her novels.

As a student at City College in the 1950s, Rossner styled herself “Jeudi” while sporting Capezio slippers and big belts, attended City College. She dropped out at 19 to marry Robert Rossner, a teacher and writer of campus crime capers with such titles as “Requiem for a School Girl.” Intent on becoming a writer herself, Rossner initially found a job in the advertising department of Scientific American but decided that the work was too interesting.

“Right away I knew I’d have to go to work in real estate or something else, or I could never finish my novel,” she said.

Sufficiently bored at her next job, as secretary at a real estate firm, she completed a first novel that was never published. After having a child, Rossner wrote her first published novel, “To the Precipice” (1966), a partly autobiographical coming-of-age story, which met with respectful reviews and low sales.

The insular “Nine Months in the Life of an Old Maid” (1969) told the story of an insane woman living in obscurity with her sister. About the time it was published, the Rossners and 19 other couples dropped out of urban life and founded a commune in New Hampshire. Life there soon soured, and the Rossners were among the 18 couples who subsequently divorced. The experience formed the basis for much unpleasant bickering in her next novel, “Any Minute I Can Split” (1972).

Rossner returned to New York and took a job as a secretary at a methadone clinic. Her immediate goal was to make money and quit working day jobs.

“I was 37 years old,” she said. “It was like being in drag. I wanted to support myself by writing.”

“Looking for Mr. Goodbar” began as a magazine assignment for Esquire about the murder of Roseann Quinn, a 27-year-old teacher. The article fell through, but Rossner turned the story into her most successful fiction. The theme, she said, was “Is it okay for women to go screwing around in big cities just because the new morality says it’s okay?” Clearly it was not.

“Goodbar” was published to tremendous publicity and jumped to no. 1 on the best-seller list. Suddenly Rossner was a celebrity author, something that didn’t quite fit her often-blunt personality. When People magazine proposed photographing her in singles’ bars, the acid Rossner refused, replying, “Would you photograph Philip Roth with a piece of liver?”

The film version of “Goodbar” starred Diane Keaton as the bar-hopping, promiscuous, and doomed Theresa Dunn, and garnered an Oscar nomination for Tuesday Weld. Although she did well on the rights, Rossner had nothing to do with the making of the film, and she detested it. A Washington Post reporter accompanied her to a screening. As the film ended, Rossner was quoted as saying, “I’d like to get out of here without having to talk to the producer.” She added, “I feel like the mother who delivered her 13-year-old daughter to the door of Roman Polanski and didn’t know what was going to happen.”

Freed forever from day jobs, she continued to write. Her much-anticipated follow-up was “Attachments” (1977), an extremely graphic story of two friends who marry Siamese-twin brothers. The critic John Leonard called it “an ambitious, disturbing novel by a best-selling author who might have written a trashy book, but decided instead to mess up our minds.” He was kinder than most, although the book remained Rossner’s favorite, “my baby.”

Rossner next published “Emmeline” (1980), a gothic tale of incest and woe set in 19th-century Maine. Again the critics were harsh, including Julian Moynahan, whose savage review in the New York Times “killed” the book, in the author’s opinion. More successful than the book was an opera version of the tale, which was produced for public television.

After “Goodbar,” Rossner’s most successful book in both sales and critical reception was probably “August” (1983), the title referring to psychiatric patients’ dilemma in the month when their doctors notoriously vanish on vacation.

Sometime after “August” climbed the sales charts, Rossner was struck with a severe case of viral meningitis that robbed her of much of her memory and left her diabetic. She said in interviews that the disease went undiagnosed for a long time because she simply thought it was psychosomatic. Rossner was for years in analysis.

After several years of recovery, she published three more novels, the wretchedly reviewed “His Little Women” (1990), an updating of the young-adult classic, as well as “Olivia” (1994) and “Perfidia” (1997), which fared better. Newsweek described “Perfidia” as “a jolting demonstration of the dangers of blind love and the literary rewards of 20/20 hindsight.”

Rossner knew she could be difficult to be around when writing, and she described herself as “a grounded and steady human being until I get deep into a book.” She maintained an office outside her home to minimize familial conflict. She married twice more, and she lived for a time in Los Angeles before returning home to New York and her extensive network of friends. She loved to read cookbooks, and at times she affected an “Isro,” as she called her Jewish Afro hairstyle.

In 1983, with “August” riding high and psychoanalysis still much on her mind, she spoke with Time magazine, sitting beneath a photo of Korean professional mourners at a funeral.

“They’re tearing out their hair and beating their breasts,” she said. “There’s a crowd in the background, but those people are only mildly sad. They don’t have to carry on; these women do it for them and let that stuff go through them at full force. And that’s what I think I do for a living – I’m a professional mourner.”

Judith Rossner

Born March 31, 1935, in Manhattan; died August 9 at NYU Medical Center; no cause of death was announced; married Robert Rossner (divorced), Mort Persky (divorced), and Stanley Leff; survived by Mr. Leff, her children, Daniel and Jean, and three grandchildren.