In the course of 120 months we have prospectively treated 45 patients with acute leukemia aged 11 to 21 years: 33 with acute lymphoblastic leukemia (ALL) and 12 with acute myelogenous leukemia (AML). Patients with ALL were treated with St. Jude's protocol XI: there were five early deaths and complete remission (CR) was achieved in 76% (89% of those completing one month of treatment); median survival (SV) was 29 months and the 120-month SV was 35%. AML patients with promyelocytic leukemia were induced to remission using all-trans-retinoic acid, whereas those with other types of AML were given the classic 7 + 3 scheme: the CR rate was 85%, median survival has not been reached and the 33 month survival was 72%. Four patients with AML were given peripheral blood stem cell autografts as part of the post-remission therapy. Our data in ALL and AML appeared to be intermediate to those in children and adults.