Protoporphyria was diagnosed in a 56-yr-old man based upon a typical clinical and family history, marked increases in erythrocyte and fecal protoporphyrin concentrations, and a marked decrease (21% of normal) in activity of hepatic heme synthase. Routine tests of liver function and histology were normal, except for a slight increase in bromsulphalein retention (9% at 45 min). Liver chemistries remained normal for 8 more years, but deteriorated rapidly when the patient was 63 yr old, with cholestasis precipitated by injury due to excess intake of ethanol. This, in turn, led to a defect in hepatic protoporphyrin excretion and to further worsening of liver injury due to porphyrin deposition. Our patient represents the 21st and oldest patient thus far reported to have died of liver failure complicating protoporphyria.