After the Second World War the number of biliary diseases has abruptly risen and lithiasis has become in many regions the most frequent surgical disease of the abdomen. At present, though there are perspectives of rational conservative treat­ ment and though endoscopic techniques permit removing some of its complications even without laparotomy, the basic treatment method still remains, and probably shall remain for long the classical surgical intervention. On the contrary, the indications for such intervention are always widening, as its risks become always smaller and the requirements for prevention higher. Many books have been written on the surgery of biliary ducts, but recent knowledge is growing so rapidly that it forces within short periods its new integration and critical assessment. Attention is mostly paid to interventions on the biliary ducts with their wide scope of problems and to the prevention and treatment of postoperative disturbances. New and more perfect diagnostic possibilities and some more suitable technical procedures as well require comparison and verification, introduce new aspects on old problems, and even change some established rules.