In a retrospective study pancreatic tissue specimens from 199 patients who had had pancreas surgery were tested for the presence of HBsAg. HBsAg could be demonstrated in two patients with chronic pancreatitis, in five patients with pancreas carcinoma and in one asymptomatic HBsAg carrier by use of the immunoperoxidase method. Demonstration of HBsAg in acinus epithelia and the small ductules supports the hypothesis, that virus particles can be produced and secreted by pancreatic tissue. The incidence of HBsAg in pancreas carcinoma (7% of cases investigated) is higher than can be explained by coincidence, thus there may be a certain association. These findings and data reported in the literature, showing that acute necrotizing pancreatitis can be caused by hepatitis virus, may lead to the conclusion, that in patients suffering from acute pancreatitis with unknown etiology serological virus diagnostics should be done.