Patients with ulcerative colitis, particularly long-standing ulcerative pancolitis, have an increased risk of developing carcinoma of the hepatobiliary tract. However, only 14 cases of carcinomas localized to the gallbladder have been associated with ulcerative colitis. Of 57 cases of gallbladder carcinomas seen at this institution, we found 3 cases in patients with ulcerative colitis, all of whom had undergone total proctocolectomy. All three patients had pancolitis, two with high-grade dysplasia, and one with low-grade dysplasia. All three gallbladders harbored an invasive adenocarcinoma. The nonneoplastic gallbladder mucosa showed a background of acalculous chronic lymphoplasmacytic cholecystitis in two cases. One of these patients also had a liver biopsy which showed changes of primary sclerosing cholangitis. Because cholecystectomy adds little to the operative morbidity and mortality of total proctocolectomy, it might be advisable to perform both operations when the latter is indicated for high-grade dysplasia in ulcerative colitis.