Three patients have been treated, with instillation of MTBE through a transcutaneous biliary drainage after transduodenal sphincterotomy. The first had gallbladder stones, the second common bile duct stones and the last intrahepatic stones (V segment). While in the first case there has been only a partial success in the other two we have obtained a total dissolution of the stones, with complete clinical recovery. This treatment has not caused immediate side effects but the absence of long term damage has not yet been proven. We think that the use of MTBE is not indicated in gallbladder stone disease. Its major indication is the dissolution of ductal gallstones when transduodenal sphincterotomy and endoscopic removal of the stones have failed.