AIM To evaluate the safety and efficacy of limited endoscopic sphincterotomy (ES) before placement of selfexpandable metal stent(SEMS).METHODS This was a retrospective analysis of 244 consecutive patients with unresectable malignant biliary obstruction, who underwent placement of SEMSs following limited ES from December 2008 to February 2015. The diagnosis of malignant biliary obstruction and assessment of patient eligibility for the study was established by a combination of clinical findings, laboratory investigations, imaging and pathological results. All patients were monitored in the hospital for at least 24 h following endoscopic retrograde cholangio pancreatography(ERCP). The incidence of immediate or early post-ERCP complications such as post-ERCP pancreatitis(PEP) and bleeding related to limited ES were considered as primary outcomes. Also, characteristics and complications according to the cancer type were classified.RESULTS Among the 244 patients included, the underlying diagnosis was cholangiocarcinoma in 118 patients,pancreatic cancer in 79, and non-pancreatic or nonbiliary malignancies in the remaining 47 patients. Early post-ERCP complications occurred in 9 patients(3.7%), with PEP in 7 patients (2.9%; mild, 6; moderate, 1) and mild bleeding in 2 patients (0.8%). There was no significant association between the incidence of post-ERCP complications and the type of malignancy(cholangiocarcinoma vs pancreatic cancer vs others, P = 0.696) or the type of SEMS used (uncovered vs covered, P = 1.000). Patients who had more than one SEMS placed at the first instance were at a significantly higher risk of post-ERCP complications (one SEMS vs two SEMS, P = 0.031). No other factors were predictive of post-ERCP complications.CONCLUSION Limited ES is feasible and safe, and effectively facilitates the placement of SEMS, without any significant risk of PEP or severe bleeding. AIM To evaluate the safety and efficacy of limited endoscopic sphincterotomy (ES) before placement of selfexpandable metal stent (SEMS). METHODS This was a retrospective analysis of 244 consecutive patients with unresectable malignant biliary obstruction, who underwent placement of SEMSs following limited ES from December 2008 to February 2015. The diagnosis of malignant biliary obstruction and assessment of patient eligibility for the study was established by a combination of clinical findings, laboratory investigations, imaging and pathological results. All patients were monitored in the hospital for at least 24 h following endoscopic retrograde cholangio pancreatography (ERCP). The incidence of immediate or early post-ERCP complications such as post-ERCP pancreatitis (PEP) and bleeding related to limited ES were considered as primary outcomes. Also, characteristics and complications according to the cancer type were classified .RESULTS Among the 244 patients included, the underlying diag nosis was cholangiocarcinoma in 118 patients, pancreatic cancer in 79, and non-pancreatic cancer or nonbiliary malignancies in the remaining 47 patients. Early post-ERCP for 9 patients (3.7%), with PEP in 7 patients (2.9% There was no significant association between the incidence of post-ERCP complications and the type of malignancy (cholangiocarcinoma vs pancreatic cancer vs others, P = 0.696) or the type of the SEMS used (uncovered vs covered, P = 1.000). Patients who had more than one SEMS placed at the first instance were at a significantly higher risk of post-ERCP complications (one SEMS vs two SEMS, P = 0.031). Factors were predictive of post-ERCP complications. CONCLUSION Limited ES is feasible and safe, and effectively facilitate the placement of SEMS, without any significant risk of PEP or severe bleeding.