In a retrospective analysis, we studied the effects of posttransfusion hepatitis (non-A, non-B) and chromosomal leukemia upon the overall times of adult patients with acute nonlymphocytic leukemia (ANLL). Seventy-two patients treated at the University of Chicago from 1970 to 1981 were evaluable. The complete remission (CR) rate for the entire group of patients was 33%, and the median survival was 246 days. Twenty-eight patients (39%) developed hepatitis, and 42 (61%) did not. The CR rate of the patients with hepatitis was 54%, and the median survival of this group was 615 days. In comparison, the CR rate for those who did not develop hepatitis was 20%, and their median survival was 136 days (p less than 0.0001). The groups were comparable in terms of race, sex, initial hematologic parameters, chromosomal abnormalities, dates of treatment, chemotherapy treatment programs, and French-American-British (FAB) subtype, but the median age of the patients who did not develop hepatitis was higher than that of the others. Patients who had normal karyotypes and who developed hepatitis had the best overall prognosis (median survival of 738 days). Patients with abnormal karyotypes who failed to develop hepatitis had the shortest survival times (median, 124 days). The group of patients who had the longest survival (median, 1130 days) included those over 40 years old, with posttransfusion hepatitis, and with normal karyotypes. The development of posttransfusion hepatitis and the presence of chromosomal abnormalities appear to be important, but opposite, indicators of overall prognosis for patients with ANLL.