Recently, the treatment using biliary stents play an important role to improve the quality of life (QOL) in patients with inoperable malignant biliary obstruction. Long-term patency is preferable, but the convenience of treatment for stent obstruction should also be considered. In this study, we investigated which stent is currently the most appropriate in hilar and extrahepatic bile duct obstruction. In hilar obstruction, metallic stents (MS) had significantly longer patency than plastic tube stents (TS). As for extrahepatic bile duct obstruction, covered MS (CMS) and MS had significantly longer patency than TS. On the other hand, many difficulties occurred when the MS was obstructed. In some of these patients, it was difficult to place the internal drainage again and their QOL was severely impaired. CMS was more convenient because it could be removed when it was obstructed. These results may suggest that MS should be used carefully in the hilar obstruction and that CMS is the best for the treatment of extrahepatic bile duct obstruction.