Abstract: Isopropanol is an important chemical to forensic pathologists in that intoxication can result in death yet presence does not necessarily indicate intoxication. Several reports have been published, which indicate that isopropanol can be created endogenously in certain situations including diabetes mellitus, starvation, dehydration, and chronic ethanol use; however, a large-scale analysis addressing all of the possible causes of postmortem isopropanol detection has not been performed. A retrospective review of all cases examined at the Bexar County Medical Examiner’s Office between 1993 and 2008 in which isopropanol was detected in routine alcohol screening was undertaken. The cases were categorized by the source of the isopropanol, and the concentrations of isopropanol and acetone were analyzed. Analysis revealed isopropanol concentrations to be low (<100 mg/dL) in cases of antemortem and postmortem creation and in postmortem contamination and high (>100 mg/dL) in cases of antemortem exposure. These results are consistent with other published reports.