Autopsy is an important educational and quality-control tool in the intensive care unit (ICU), but rates of traditional medical autopsies have declined worldwide. "Virtual" autopsy involving only advanced radiographic techniques might provide an alternative approach to postmortem examinations. To assess the value of postmortem multidetector computed tomography as an alternative to medical autopsy. Prospective cohort study. (ClinicalTrials.gov registration number: NCT01040520) 9 ICUs in a single academic medical center. Consent for both medical and virtual autopsies was sought from the families of all consecutive patients who died in the ICU between 1 January and 30 June 2010. Clinical records were reviewed to determine whether unsuspected autopsy findings would have altered care if known (major diagnosis) or would not have altered care (minor diagnosis). Of 285 patients, 47 underwent both virtual and medical autopsy. Of 196 clinical diagnoses made before death, 173 (88%) were identified by virtual autopsy and 183 (93%) by medical autopsy. Fourteen new major and 88 new minor diagnoses were detected by any autopsy method. The main diagnoses missed by virtual autopsy were cardiovascular events (9 of 72) and cancer (12 of 30). In contrast, medical autopsy missed 13 traumatic fractures and 2 pneumothoraces. Among 115 additional patients in whom only virtual autopsy was performed, 11 new major diagnoses were made. Virtual autopsy was performed in only 57% of patients (n = 162); among this group, consent for traditional medical autopsy was obtained for only one third. Virtual autopsy may be useful for identifying diagnoses that traditionally have been identified by medical autopsy. This may also hold true, at least in part, for the educational aspect of medical autopsy (confirming antemortem clinical diagnoses). Further studies are required to confirm these preliminary results. University Medical Center Hamburg-Eppendorf, Germany.