Currently the best curative therapy for primary malignant biliary tumor is surgery. Unfortunately, many patients present at a very late stage and only palliative biliary drainage is possible. Usually nonsurgical palliative biliary drainage means either percutaneous or endoscopic approach. In this series, the authors reported the rate of technical success and immediate complications in patients with malignant biliary obstruction who underwent endoscopic biliary drainage. From endoscopic retrograde cholangiopancreatography (ERCP) database between September 2000 and October 2001, there were 273 ERCP performed for obstructive jaundice. Of these, 50 patients with malignant tumor underwent 80 procedures for endoscopic biliary drainage. The patients were divided into three groups according to the cholangiographic findings and clinical diagnoses. Patients with carcinoma of the pancreatic head were categorized as group I (n=10). Group II (n=20) and III (n=20) were patients with extrahepatic cholangiocarcinoma and hilar cholangiocarcinoma respectively. All patients received either plastic or metallic endoprothesis placement for biliary drainage. All patients except two in group I had successful endoscopic treatment. Complications in group I, II and III were 15.4 per cent, 14.3 per cent and 53.1 per cent respectively. Only one patient in group II developed significant hypotension during the procedure. Another complication was defined as post procedure cholangitis. In conclusion endoscopic biliary drainage was technically feasible in 97.5 per cent of patients who had malignant biliary obstruction. In patients with hilar tumor the incidence of post procedure cholangitis was high (53.1%). Improvement in technique, avoiding unnecessary contrast injection, and draining the obstructed bile duct after injecting the contrast may improve the outcome and decrease the rate of post procedure cholangitis in these patients.