During the last 8 years, the authors had experience with 10 cases of carcinoma of the gallbladder with an anomalous connection between the choledochus and the pancreatic duct. These cases were studied in reference to age, sex, frequency of gallstones and dilatation of the bile duct, amylase levels in bile, direct cholangiograms, histologic findings, methods of treatment, and prognosis. Histologically, intestinal metaplasia was noticed in cancerous areas and also in noncancerous areas of differentiated adenocarcinomas. These facts suggest that in carcinoma of the gallbladder with this anomaly, reflux and stasis of pancreatic juice in the gallbladder may induce chronic cholecystitis which leads to mucosal metaplasia and, eventually, to differentiated adenocarcinoma.