She is chiefly remembered for her lengthy affair with the poet Vita Sackville-West, which the two women continued after their respective marriages.
This was featured in novels by both parties; in Virginia Woolf's novel Orlando: A Biography, and in many letters and memoirs of the period, roughly 1912–1922.
She was also the inspiration for Lady Montdore in Nancy Mitford's Love in a Cold Climate and Muriel in Harold Acton's The Soul's Gymnasium.
Trefusis published many novels of her own, as well as non-fiction, both in English and French.
Although some of her books sold well, others were unpublished, and her overall critical heritage remains lukewarm.