摘要Background: To date, there is controversy regarding unilateral versus bilateral stent placement in patients with malignant hilar biliary strictures (MHBSs). The aim of this study was to compare the clinical out- comes and complications of unilateral and bilateral (stent-in-stent method) stent placements for these patients.Methods: We conducted a multicenter retrospective analysis of patients with inoperable MHBS who un- derwent endoscopic self-expandable metal stent (SEMS) placement from January 2009 to December 2019. Two groups classified according to the stent procedure method were compared for demographic, proce- dural, and postprocedure factors. Survival analysis for patency loss and overall survival was also con- ducted. Results: A total of 236 subjects were included. A superior technical success rate was found in the unilat- eral stent group (98.8％ vs. 82.5％, P < 0.001), whereas the clinical success rate was higher in the bilateral group (85.7％ vs. 70.5％, P = 0.028). There was no significant difference with respect to complications or patency loss, and the bilateral group had better overall survival ( P < 0.01). In the Cox proportional hazard model, MHBSs from lymph node compression were associated with a higher risk of death (HR = 9.803, P = 0.003). In contrast, bilateral SEMS insertion showed reduced postprocedural mortality (HR = 0.316, P = 0.001). Conclusions: Y-type stent-in-stent bilateral SEMSs are technically difficult but demonstrated more fa- vorable overall survival for palliative bile drainage of inoperable MHBS patients compared to unilateral insertions.