Her 1956 book The Nun's Story was a best-selling novel which was made into an award-winning 1959 movie starring Audrey Hepburn and Peter Finch.

Another work, The Undiscovered Country: A Spiritual Adventure published by Little, Brown & Co. was a description of her years as a student of mystic G. I. Gurdjieff and her eventual conversion to Catholicism.

Hulme studied with Gurdjieff as part of a group of eight women known as "The Rope," which included: Solita Solano, Kathryn Hulme, Alice Rohrer, Elizabeth Gordon, Louise Davidson, Georgette Leblanc, Margaret Caroline Anderson and Jane Heap[1] She is also the author of The Wild Place, a vivid description of her experiences as the UNRRA Director of the Polish Displaced Persons camp at Wildflecken, Germany, after World War II.

[2] It was at Wildflecken that Hulme met a Belgian nurse and former nun Marie Louise Habets, who became her lifelong companion.

In her 1938 fictionalized autobiography We Lived as Children, Hulme describes a child's perspective of San Francisco after the 1906 earthquake.