When cholelithiasis and gastroduodenal disease coexist, the surgeon must decide whether it is appropriate to perform a cholecystectomy at the same time as gastric surgery. The decision should be based on whether simultaneous cholecystectomy increases the risk of gastric surgery. We examined 38 patients who had undergone gastric resection or total gastrectomy and simultaneous cholecystectomy, and 38 patients who had undergone gastric surgery without cholecystectomy during the same period of time, who served as matched controls. The two groups were compared with respect to duration of operation, plasma and blood units transfused during and after surgery, duration of postoperative hospital stay, postoperative complications and mortality. Results regarding the two groups were compared by statistical tests. Analysis of the results did not reveal any significant differences between cases and controls, but the power of the test was quite low (1-β = 0.4). The results thus do not allow any final conclusion, but they would seem to support the possibility that simultaneous cholecystectomy does not increase the risks of gastric surgery