After graduate school, Mason wrote The Girl Sleuth: A Feminist Guide to the Bobbsey Twins, Nancy Drew, and Their Sisters (1975) about her favorite childhood reading; then, in her late thirties, she started writing short stories. In 1980 The New Yorker published her first story. "It took me a long time to discover my material," she says. "It wasn’t a matter of developing writing skills, it was a matter of knowing how to see things. And it took me a very long time to grow up. I’d been writing for a long time, but was never able to see what there was to write about. And I always aspired to things away from home, so it took me a long time to look back at home and realize that that’s where the center of my thoughts was." Mason writes about the working-class people of western Kentucky, and her stories have contributed to a renaissance of regional fiction in America, creating a literary style that critics have labeled "shopping mall realism."

Mason’s first collection, Shiloh and Other Stories, won the 1982 Hemingway Foundation Award. In 1985 reviewers of her novel In Country compared her to Ann Beattie and other "writers of her generation who chronicle aimless lives in prose that tends to be as laconic and stripped down as her characters’ emotional range." Mason doesn’t regard herself as a feminist writer, despite the heroine in her often reprinted story "Shiloh." She feels that she writes about ordinary people