She wrote two novels, both of which were not published until she was in her sixties: The Ten Thousand Things (De tienduizend dingen 1955) and Days Before Yesterday — also published as Just Yesterday (Nog pas gisteren 1951). There are English translations of her novels by Hans Koning. Some of her short stories were published in translation in magazines such as Vogue during the 1960s. In Dutch, five short-story collections by her were also published.
Dermoût is arguably one of the great "what-ifs" of twentieth-century literature: she turned to writing early in life, but remained largely unpublished until she was 63.
As things stand, she is viewed as one of the giants among Dutch-Indies literary writers, and The Ten Thousand Things in particular is widely regarded as an idiosyncratic masterpiece. As Hans Koning puts it in his Introduction to the New York Review Books edition of the novel:
"Dermoût was sui generis, a case all her own. She did not write about her Indies as a Dutch woman, or as a Javanese or an Ambonese. Hers was a near-compassionate disdain for the dividing lines, the hatreds and the fears ... She painted landscapes, still lifes and people in a world of myth and mystery."
The book has been translated into thirteen languages.
Although not conventionally autobiographical, both of her novels draw from Dermoût's own life. In particular, like the central character in The Ten Thousand Things, Dermoût lost her son in violent circumstances (he died in a Japanese prisoner-of-war camp). The Javanese childhood experiences and reminiscences described in Days Before Yesterday are based on, but do not mirror, her own childhood in the tropics.
She is the subject of the biography Geheim Indië. Het leven van Maria Dermoût 1888-1962 ("The Secret East Indies. The Life of Maria Dermoût 1888-1962")  by the Indo (Dutch-Indonesian) author Kester Freriks.