Phenobarbital (PB) has a reputation for safety, and it is commonly believed that PB-related increases in serum aminotransferase levels do not indicate or predict the development of significant chronic liver disease. Here we report of two adult patients with a long history of epilepsy treated with PB who died suddenly: one as consequence of cardiac arrest, the other of acute bronchopneumonia. At autopsy, analysis of liver parenchyma revealed rich portal inflammatory infiltrate, which consisted of mixed eosinophil and monocyte cells, associated with several foci of necrosis surrounded by a hard ring of non-specific granulomatous tissue. Inflammatory reactions of internal and external hepatic biliary ducts were also seen. Our findings illustrate that PB may be associated with chronic liver damage, which may lead to more serious and deleterious consequences. For this reason, each clinician should recognize this entity in the differential diagnosis of PB-related asymptomatic chronic hepatic enzyme dysfunction.