Her work found recognition in literary magazines such as The Bookman and The Little Review, as well as from fellow modernists, T. S. Eliot, H.D.

During the early 1920s Butts was mostly in Paris, where she became friends there with several writers and artists, including the painter Cedric Morris (a friend of her brother) and the artist, poet, and filmmaker Jean Cocteau,[7] who illustrated her book, Imaginary Letters (1928).

[8] In mid-1921 she and Maitland spent about twelve weeks at Aleister Crowley's Abbey of Thelema in Sicily; she found the practices there shocking, and came away with a drug habit.

In 1928, Butts published Armed with Madness a novel featuring experimental Modernist writing revolving around the Grail legend.

After a time in London and Newcastle, they settled in 1932 at Sennen on the Penwith peninsula on the western tip of Cornwall, but by 1934 the marriage had failed.

[4][13] Butts was an ardent advocate of nature conservation, and attacked the pollution of the English countryside in her pamphlets Warning To Hikers and Traps For Unbelievers.

[2] In 1933, at Sennen, she was introduced to the young novelist, Frank Baker, by George Manning-Sanders.

She died on 5 March 1937, at the age of forty-six, at the West Cornwall Hospital, Penzance, after an operation for a perforated gastric ulcer.

Mary Butts's papers are held at the Beinecke Library at Yale University.