OBJECTIVES: Partially covered self expandable metal stents (SEMS) and polyethylene stents (PES) are commonly used for distal malignant biliary obstruction. SEMS are more efficacious yet expensive than PES. The cost-effectiveness of both stents using contemporary estimates was assessed. METHODS: A decision tree comparing initial palliative placement of PES versus SEMS was constructed for patients with distal malignant biliary obstruction requiring palliation with one-year follow-up. Patients underwent an endoscopic retrograde cholangiopancreatography (ERCP) to insert the initial stent, and were followed by a gastroenterologist every 3 months. If the insertion failed, a percutaneous transhepatic cholangiogram was performed. If stent occlusion occurred, a PES was then inserted at repeat ERCP, either in an outpatient setting, or after admission to hospital if cholangitis was present. Effectiveness was expressed as the likelihood of no occlusion. Costs were measured in US dollars.  Probabilities were issued from a recent published randomized clinical trial. RESULTS: A PES-first strategy was dominated by a SEMS-first approach. The average cost was $6,541 USD for initial SEMS and $19,054 USD for initial PES, associated with respective effectiveness probabilities of 65.6% and 13.9% (likelihood of experiencing no occlusion over 12 months). Sensitivity analyses confirmed the robustness of these results.  They are however limited by the randomized trial where the probabilities were derived from, with regards to sample size and generalizability.  CONCLUSIONS: At the time of initial endoscopic drainage for patients with malignant biliary obstruction undergoing palliative stenting, an initial SEMS approach is both more effective and less costly than a PES-first strategy, regardless of anticipated survival or cost setting