Objective To evaluate the safety and efficacy of simultaneous endoscopic bilateral placement of selfexpandable metal biliary stents in malignant hilar biliary obstruction． MethodFrom May 2007 to December 2010, a total of 24 patients with hilar malignancy of Bismuth type Ⅱ to Ⅳ underwent endoscopic retrograde cholangiopancreatography (ERCP) and bilateral metal stent placement. Technical success rate, functional success rate, ERCP related complications, stents’ patency time, and patient’ survival time were recorded and reviewed． Results Twentyone of 24 patients were followedup for average 39 months. Technical success rate was 100%, the average operation time was （36.2±13.9） min, the functional success rate was 95.45%. Mild cholangitis occurred in 2 cases and there was no ERCP related pancreatitis, bleeding, perforation, and death. Stents dysfunction occurred in 7 within followup period. Amonge them, plastic stents were inserted through the metallic stents in 4 cases, PTCD was required in 1 case, and conservative therapy was given in the other 2 cases. The median stent’ patency time and median patient’ survival time were 253 d (95% CI: 199.79-306.21) and 229 (95% CI : 154.53-303.47）, respectively, with no significant differences between Bismuth classification types. ConclusionEndoscopic simultaneous bilateral biliary metal stent placement is technically feasible, safe, and effective to malignant hilar obstruction.