This is a report on our experience in 309 percutaneous fiberendoscopies of the biliary tract done in 106 patients of the 115 scheduled for the procedure. We describe the relevant approaches, techniques, complications and results. In particular, percutaneous transhepatic cholangioscopies (PTCS) were accomplished on transhepatic percutaneous drainages located radiologically in 35 patients: in 13 for differential diagnosis to distinguish between malignant and benign stenoses (diagnostic accuracy in 92% of the biopsies), in 22 cases with therapeutic intent, including 14 lithotomies for extrahepatic biliary tract calculosis, combined in 4 cases with a simple dilatation of the papilla and a percutaneous "descending" papillotomy; in 7 patients a dilatation of the biliary tract (BT) or of the stenosis of a biliodigestive anastomosis was accomplished (malignant in 4 patients, benign in 3 patients). In 38 patients postoperative percutaneous transhepatic cholangioscopies were performed along surgically located transparietohepatic drains, both to assess the biliodigestive anastomosis healing process carried out by two different techniques (30 patients), and to complete the biliary tract drainage as part of the primary and secondary endoscopic surgical treatment of massive intrahepatic lithiasis. In two further patients affected by such pathology, PTCS was done in combination with fibercholangioscopy performed via a transjejunal approach using a Völker drain on a Y-shaped loop. Nine of these patients were treated successfully and one patient later underwent a left hepatectomy, since attempts to drain that area had remained unsuccessful. The transjejunal approach was carried out in 3 patients as a diagnostic measure: in two cases to check the lithotomy, and in one case to check a cholangiojejunal anastomosis.(ABSTRACT TRUNCATED AT 250 WORDS)