Angiosarcoma of the liver was diagnosed at autopsy in a 50 year old female with insulin-resistant diabetes mellitus. Over the course of 27 years, the patient received 27 l of Insulin-preparations applied subcutaneously and by an intraperitoneal pump-system. The preparations contained 20 g phenol. Known carcinogens for angiosarcoma of the liver-thorotrast, monovinylchloride or arsenic-were excluded. Phenol is a well known carcinogen of the skin and its tumor-promoting potential has been demonstrated in vitro. We suggest phenol as a potential aetiologic factor for angiosarcoma of the liver.