ObjectiveTo determine if autopsies performed on patients who die in the medical intensive care unit (ICU) provide clinically important new information.DesignRetrospective review.SettingA 16-bed medical-coronary ICU.PatientsPatients who underwent autopsy during a 1-yr period.InterventionsPre mortem diagnoses were determined from the medical record. Autopsy results were obtained from the final pathology report. A panel of three physicians with certification of added qualifications in critical care medicine reviewed the findings.Measurements and Main ResultsThese questions were asked: a) Is the primary clinical diagnosis confirmed? b) Are the clinical and pathologic causes of death the same? c) Are new active diagnoses revealed? and d) If the new findings had been known before death, would the clinical management have differed?Forty-one autopsies (31% of deaths) were done that showed: a) the same primary clinical diagnosis and post mortem diagnosis in 34 (83%) patients; b) the same clinical and pathologic cause of death in 27 (66%) patients; c) new active diagnoses in 37 (90%) patients; and d) findings that would have changed medical ICU therapy had the findings been known in 11 (27%) patients.ConclusionsAlthough the primary clinical diagnosis was accurate in most cases before death, the cause of death was frequently unknown. Almost all autopsies demonstrated new diagnoses, and knowledge of these new findings would have changed medical ICU therapy in many cases. In the critical care setting, autopsies continue to provide information that could be important for education and quality patient care. (Crit Care Med 1998; 26:1332-1336)