We studied the effectiveness of low-dose, oral administration of etoposide for maintenance chemotherapy of patients with adult T cell leukemia (ATL). Sixteen patients (9 males and 7 females) in remission (9 in complete remission and 7 partial remission) were orally administered 25 or 50 mg/day of etoposide. Median response duration of all the patients to the therapy was 18.6 months, ranging from 5.0 to 34.0 months. Thirteen out of the 16 patients relapsed, and 9 of them died of tumor progression. Appetite loss occurred in one case, without any other severe side effects. It has been suggested, therefore, that oral administration of the etoposide is useful for maintenance chemotherapy in ATL patients.