38 cases of acute leukemia were treated with autologous bone marrow transplantation (ABMT). The marrow was purged with hyperthermia of 42 degrees C in vitro for one hour in microwave. Twenty-two among them were AML (CR1). Sixteen were ALL (CR1). The mean age was 26 (10-43) years. All the patients were engrafted successfully after ABMT. Mean DFS was 21 (3-69) months. Four cases relapsed at 3 to 8 months after ABMT. Two patients with ALL developed central nervous system leukemia at 12 and 15 months respectively after ABMT. The DFS and probability of relapse at 5 years were 67.8% and 16.8% respectively for all patients.