Detection of HBs-Ag in the pancreatic juice in acute and chronic hepatic failure caused by hepatitis-B-infection leads to the assumption that parts of that virus are produced by the pancreas. We investigated pancreatic tissue obtained during Whipple's procedure in 51 cases of pancreatic carcinoma. In 5 specimens HBs-Ag was detected, mostly located in acinar cells and inside small ducts. In view of our knowledge of the carcinogenesis of human hepatocellular carcinoma, hepatitis B virus could produce an oncogenic effect in pancreatic carcinoma, too.