Seven patients experiencing first (n = 5) or second (n = 2) relapse of acute promyelocytic leukemia (APL) were treated with a new synthetic retinoid, Am-80. All 7 patients were previously treated with all-trans retinoic acid (ATRA). Am-80 was orally administered at a dose of 6 mg/m2 daily. Chemotherapy was combined in 3 patients because of leukocytosis. All 7 patients achieved a complete remission (CR) during periods ranging from 36-56 days (median 52 days). Adverse effects such as hyperlipidemia and skin lesions, were tolerable. After achieving CR, 3 patients underwent allogeneic bone marrow transplantation and 4 patients received only consolidation chemotherapy. In 2 of 3 patients who received allogeneic transplantation, relapse free survival has lasted for 9.7 and 28.3 months. Furthermore, in 2 of 4 patients who received only chemotherapy, relapse free survival has lasted for 84.7 and 90.1 months. Am-80 is an active agent for APL patients who have relapsed from ATRA-induced remission.