From 1965 to 1980, reoperations for residual or recurrent stones were performed on 78 out of 962 Japanese patients with cholelithiasis. The majority of patients who required reoperation had intrahepatic stones. Most of the causes of reoperation were residual stones due to incomplete removal or the non-detection of intrahepatic stones at the previous surgery. Very careful examination of the intrahepatic biliary trees should be done in patients with biliary tract diseases, because in many, the first operation was done during their youth. To remove the intrahepatic calculi completely, hepatic lobectomy should be considered as a final procedure. The causes of reoperation of common duct stones were residual in 60 per cent and recurrent in 40 per cent. Definitive surgery should be done at the first or at least the second operation to avoid irreversible hepatic disorders which have untoward effects on the prognosis. It is important not only to remove the stones but also to relieve the bile stasis in the biliary tract.