High-dose cyclophosphamide, 1,3-bis-(2 chloroethyl)-1-nitrosourea (BCNU), and VP-16-213 followed by autologous bone marrow rescue was administered to 29 adult patients with acute leukemia in relapse who had failed to respond to prior salvage treatment, with the following results: 14 patients (48%) achieved complete remission (CR), two patients died early of infection and hemorrhage during hypoplasia, and 13 patients had relapsed with leukemia after an initial hypo-plastic phase. Median remission duration was 3 1/2 months (range, 1-8 months). Maintenance treatment with cyclophosphamide and VP-16, which was given to six patients, did not prolong remission duration. Subsequent salvage treatment was well tolerated by both responders and patients who failed to reach CR. This regimen, which is active in both acute lymphocytic leukemia and acute myelogenous leukemia, had a mild toxicity.