To determine the safety and efficacy of percutaneous intraductal radiofrequency ablation (RFA) combined with biliary metal stent placement for patients with unresectable malignant biliary obstruction. From a cohort of 70 patients with unresectable malignant biliary obstruction, 28 patients received percutaneous intraductal RFA combined with biliary stent placement (group A) and the remaining 42 were treated with biliary metal stent placement only (group B). Stent patency, overall survival (OS), alleviation of jaundice, and postoperative complications were assessed. The technical success rate for both groups was 100%. No severe complications (e.g., biliary bleeding, perforation) occurred. In both groups, jaundice was relieved and the decrease of the total and direct bilirubin concentration was significant (p < 0.01). The median time of stent patency in group A and group B were 6.6 ± 0.3 months (95% CI 6.1-7.1 months) and 4.9 ± 0.4 months (95% CI 4.2-5.6 months), respectively (p < 0.01). The median overall survival times in Group A were 7.2 ± 0.3 months (95% CI 6.5-7.9 months) versus 5.6 ± 0.4 months (95% CI 4.8-6.4 months) in group B (p < 0.01). In univariate and multivariate analyses, intraductal RFA, stent patency, and decreased baseline serum direct bilirubin concentration were associated with greater OS (p < 0.05). Percutaneous intraductal RFA combined with stent placement is a safe and effective method for patients with malignant biliary obstruction. As compared to stent placement alone, percutaneous intraductal RFA can significantly prolong stent patency and improve the overall survival of patients with malignant biliary obstruction.