A series of 477 choledochotomies for suspected choledocholithiasis is presented. The indications for exploration of the common bile duct are reviewed. Absolute indications are: palpable stones in the common bile duct, stones seen on intravenous cholangiography and jaundice during the operation. When there are only relative indications, an intraoperative pre-exploratory cholangiogram should be performed so that unnecessary exploration can be avoided.