32 forceps biopsies were performed in 30 patients with obstructive jaundice during percutaneous transhepatic biliary drainage procedures. In one patient an adequate specimen could not be obtained. In 25 of the remaining 31 cases diagnosis was confirmed histologically (malignant tumours: n = 22, benign stricture: n = 3). In 6 patients false-negative results were obtained. Transluminal biopsy is an easily performed adjunct to percutaneous transhepatic diagnostic interventions with minimal additional discomfort for the patient. In many cases percutaneous needle biopsy can be avoided. Forceps biopsy enables nonoperative histological diagnosis of small carcinomas of the bile ducts.