Caffeine is a central nervous system stimulant that is consumed by large numbers of people on a routine basis, usually in the form of coffee or tea. However, if consumed in high doses, this xanthine alkaloid is profoundly toxic and can result in death. Increasingly being sold as a dietary supplement, many people, particularly those in the health and fitness community, where it is touted as a fitness and muscle building aid, are consuming caffeine anhydrous on a daily basis. We report a case of fatal caffeine overdose in a 39-year-old man resulting from the self-administered ingestion of approximately 12 g of pure caffeine anhydrous. Autopsy blood caffeine levels were 350 mg/L. We recommend mandated labeling of pure caffeine anhydrous, highlighting the toxicity risk of ingesting this chemical; and we recommend ensuring that caffeine levels are included in the comprehensive forensic toxicology panel performed on all cases.