The value of a routine intraoperative cholangiogram is controversial. We reviewed 352 consecutive instances of cholecystectomy for nonmalignant disease during a period of three years to assess the diagnostic accuracy and additional cost of the roentgenographic technique. Intraoperative cholangiogram was done in all except 11 patients. Forty-nine of 341 patients underwent exploration of the common bile duct. The diagnosis was determined by the cholangiogram and was correct in 46 patients with three false-positive results. The other 292 patients did well without exploration of the common bile duct. The cholangiocatheter and a special cholangioclamp made the procedure easy and minimized additional operation time (five minutes with no mortality and negligible morbidity). Clinical indications for exploration of the common bile duct correlated poorly with abnormal findings in the bile duct. Unsuspected common duct stones were detected by cholangiogram in 17 (5 per cent) patients. Possible iatrogenic trauma to the common duct was prevented when significant abnormal findings were demonstrated by cholangiogram. The results of this study indicate that routine intraoperative cholangiogram is: accurate for diagnosis of common bile duct stones; useful in identification of bile duct anomalies and, thus, aids in preventing injury to the common bile duct; safe with negligible risk, and neither expensive nor time consuming if done correctly as a routine procedure.