In a retrospective post-mortem study the connection between the post-cholecystectomy state, cholelithiasis and carcinoma of the large intestine was evaluated in 333 cases and compared with an age and sex matched control group and a group with gastric carcinoma. It was established that cholelithiasis (without cholecystectomy or contracted gallbladder) occurred significantly more frequently (24.9%) in patients with colonic carcinoma than in the control group (15.3%) or the gastric carcinoma group (12.6%) (P less than 0.001). In contrast the rate of cholecystectomy in patients with colonic carcinoma was not significantly increased (6.3%) when compared with both control groups (4.6 and 4.8%). Separate assessment of males and females showed that females had cholecystectomy and contracted gallbladder significantly more frequently (P less than 0.05). These figures suggest that the clinically observed association between cholecystectomy and colonic carcinoma reflects only a - not necessarily causative - connection between gallstone disease and colonic carcinoma.