One of Gertrude Stein's most important and controversial works, written in 1933, first appearing in The Atlantic Monthly, and later published in book form. Despite the title, it is actually Gertrude Stein's autobiography, as told through the voice of her lover, Alice B. Toklas. Using Alice as narrator, Gertrude engages in biography, history, observation, gossip, and self-aggrandisement, all tempered with ironic humor. It was in this work that Gertrude Stein first described herself to the world as a genius. It was also this work that first brought attention to Alice B. Toklas and revealed her role as Gertrude's nurse, cook, maid, secretary, and confidant, with subtle hints that she was also her lover. This latter point was confirmed by the publication of the women's love poems and letters decades later.

Autbiography's other significance lies in its insightful portrayals of the many legendary figures who visited the two women, including Ernest Hemingway, Sherwood Anderson, Pablo Picasso, Henri Matisse, and Georges Braque, though it is sometimes hard to determine what is gossip or humor and what is fact. The book also gives an excellent picture of Paris during and after the First World War, including an account of Gertrude's and Alice's involvement with the American Fund for the French Wounded and their visits to French hospitals, for which they were decorated.

Several of the artists and writers portrayed in the book apparently did not share Gertrude Stein's sense of humor. In 1935 they collaborated on their own counter-attack, titled Testimony Against Gertrude Stein.