Ten patients with acute promyelocytic leukemia (APL) were treated with all-trans retinoic acid (ATRA). Eight of 10 patients achieved complete remission (CR), and among the 8 newly diagnosed cases, 7 achieved CR. Five of 8 CR cases remained in CR after 8 to 30 months. Except for hypotension and a large gastric ulcer resulting from hyperhistaminemia, the adverse effects of ATRA were generally mild. Severe thrombotic tendency occurred in a patient treated with ATRA combined with tranexamic acid. Intensive chemotherapy consisting of daunorubicin (DNR) and other agents was scheduled for the patients who achieved CR with ATRA.