Thirty-five patients with acute nonlymphocytic leukemia (ANNL) entered complete remission (CR) and survived 16 weeks following induction therapy with high-dose timed sequential chemotherapy without maintenance therapy. These patients were analyzed to test the hypothesis that acute posttransfusion hepatitis (APTH) has a beneficial influence on the course of ANNL. Ten patients developed evidence of APTH while 25 did not. Median length of CR was 22 weeks for both groups while median survival was longer in patients not developing APTH (75 weeks vs 58 weeks) (P greater than 0.5). Possible explanations for the discrepancy between these results and those previously reported are discussed.