Covered metallic stent (covered MS) is useful to improve quality-of-life in patients with unresectable malignant distal biliary obstruction. We have managed 129 patients with three types of covered MS; polyurethane-covered Wallstent (hand-craft), polyurethane-covered Diamond stent (hand-craft), and silicone-covered Wallstent (commercially available). They were compared with 115 cases treated with uncovered metallic stent (uncovered MS). There was no significant difference in survival between the two groups. The cumulative stent patency was significantly higher in the covered MS group than uncovered MS group (P = 0.0027). Stent occlusion occurred in 17 patients (13%) in the covered MS group, and in 48 patients (42%) in the uncovered MS group (P < 0.0001). Complications of covered MS were 8 (6%) in acute cholecystitis, 10 (8%) in acute pancreatitis, and 10 (8%) in migration. We evaluated the risk factors for these complications of covered MS.