Because of concerns about the declining autopsy rate, an attempt was made to evaluate the contributions from the postmortem examination in a pediatric population with leukemia. Accordingly, 161 autopsies performed between 1970 and 1985 were reviewed and the diagnoses compared with those listed in the clinical records of the same patients. New diagnoses were grouped into diagnoses of diseases thought to have contributed to the death of the patient, those of diseases thought to have contributed to the morbidity of the patient, those of presumed toxic reactions to drug therapy, and diagnoses of academic interest. The newly diagnosed diseases thought to have contributed to the patient's death either had been totally unsuspected by the clinician or had been suspected but incorrectly diagnosed. The most common revelation was the identification of mycotic infections that were thought by the clinician to have been bacterial in origin. The clinical diagnosis of these kinds of infections progressively improved during the study period. Because the changes in diagnoses and therapy, particularly the increasing use of antimycotic therapy, could be directly attributed to autopsy findings and, more recently, because of the expanding use of more toxic multiagent chemotherapy, we believe that the postmortem examination remains an important procedure, even in clinical situations where much is known about the patient.