A retrospective case-control study was carried out to assess whether additional cholecystectomy in patients undergoing digestive surgery caused increased postoperative morbidity and mortality. During the period 1983-90, 70 patients underwent cholecystectomy at the same time as other surgery (25 gastric resections, 23 colon resections, 17 total gastrectomies, 2 fundoplicatio using Nissen's technique, 2 cases of Heller's operation, 1 truncular vagotomy and pyloroplasty). These cases were matched for sex, age (+/- 5 years) and type of primary operation with 70 controls (patients without additional cholecystectomy). Complications were significantly more frequent among the former group compared to controls (28.6% vs 11.4%, p = 0.02), in particular in the group of patients undergoing colon resection (34.8% vs 8.7%, p = 0.04). The frequencies of reoperation and mortality were also higher in patients undergoing additional cholecystectomy than in controls (10% vs 1.4%), but the difference was not statistically significant (p = 0.06). In conclusion, additional cholecystectomy during digestive surgery increases the risk of postoperative complications, in particular in colorectal surgery.