One hundred fifty-one children with acute myelogenous leukemia (AML) entered the cooperative study BFM-78 between December 1978 and October 1982. The initial therapy consisted of an intensive induction and consolidation regimen over eight weeks with seven different drugs and cranial irradiation. It was followed by maintenance with thioguanine and cytosine arabinoside for two years and additional Adriamycin during the first year. One hundred nineteen (79%) patients achieved a complete remission. Thirteen (9%) children died of early hemorrhages. After a median follow-up time of 36 (12 to 57) months, 47 relapses have occurred, with CNS involvement in seven cases. The life table analysis revealed a probability for overall survival after almost five years of 45% (SD, 4%), for event-free survival 41% (SD, 4%), and for the event- free interval 52% (SD, 5%). Up to now, no relapse was seen after 2 1/2 years. Risk factor analysis showed that early fatal hemorrhages occurred predominantly in children with M5 FAB type and with initial leukocytosis. An initial high WBC count and liver enlargement were unfavorable parameters for achieving remission. No factors could be identified concerning the risk for relapse. These data indicate that the applied treatment strategy is successful in inducing complete remissions in about three fourths of children with AML and also in enhancing considerably the chances for long-term remission.