Background: The clinical course of hypopigmented mycosis fungoides has not been well described. Objective And Methods: We sought to review the management and follow-up of patients with hypopigmented mycosis fungoides evaluated between January 1990 and August 1998. Results: There were 7 African American and 2 Asian patients (5 male and 4 female patients); 8 had stage Ia and 1 had stage Ib disease. The mean age at diagnosis was 34.4 years, the mean latent period was 9.2 years, and the mean follow-up period after diagnosis was 6.5 years. Treatment modalities used included psoralen UVA, UVB, and topical mechlorethamine. Eight had complete clinical responses, and another had a partial response. The remission period ranged from 2 months to 3 years. In all but one patient, lesions recurred; all responded rapidly to another course of therapy. Conclusion: Hypopigmented mycosis fungoides is characterized by early onset, occurrence in dark-skinned individuals, and good response to therapy. Recurrences are common. In most, it has a biologically benign course. (J Am Acad Dermatol 2000;42:33-9.)