This study was performed to evaluate clinical outcomes and factors associated with patency of self-expanding metal stents (SEMS) in patients with malignant upper gastrointestinal (UGI) obstruction. In 83 patients with malignant UGI obstruction, 118 SEMS placements were performed. Obstruction sites were esophagus/gastro-esophageal junction (GEJ) and gastric outlet (GO) in 41 and 42 patients, respectively. Technical success was achieved in 99.2% and clinical success in 90.5%, with no procedure-related complications. Re-obstruction and migration occurred in 38.1% during a mean follow-up of 137 days; both occurred significantly more often with GO than esophageal/GEJ obstruction (49.2% vs 23.9%). Patency rates of esophageal/GEJ obstruction were 93.5, 78.1 and 67.0% at 30, 90 and 180 days, respectively, and were significantly higher than those of GO obstruction-71.7, 51.8 and 32.5%. Palliative chemotherapy or radiation therapy was not associated with stent patency. Endoscopic SEMS placement is a safe and effective palliative treatment for malignant UGI obstruction, and complications or stent patency differed according to obstruction site.