Background: Endoscopic biliary stenting (EBS) is accepted as an effective palliative drainage procedure for malignant bile duct obstruction (MBDO) and the prerequisites for success are selective bile duct cannulation, guide wire passage across the stricture, and accurate stent placement in the bile duct. Of these, difficult guide wire passage is a main cause of failure. Although successful guide wire passage is influenced by the endoscopist's experience of using guide wire, it may depends on the cholangiographic characteristic of stricture itself. Aim: To determine whether characteristic of stricture influence on the success rate of guide wire passage across the malignant biliary stricture. Methods: To define cholangiographic characteristic of stricture, complete review of endoscopic retrograde cholangiograms of 126 patients (59M/67F, age range 49-88, mean 67.4 years) with MBDO treated with EBS during the past 5 years was done by biliary endoscopist and abdominal radiologist. Etiology of stricture included bile duct cancer (n=74), pancreatic cancer (n=30), gallbladder cancer (n=17), and metastasis (n=5). The “Shape” of stricture was classified as infiltrating, nodular, nodular-infiltrating (mixed), and papillary (Sakamoto et al, Ann Surg 1998), the “location” as upper, mid, and lower third of the common bile duct, and the “lengh” as <1 cm, 1-3 cm, and >3cm. The success rate of guide wire passage according to the cholangiographic characteristics mentioned above was assessed and compared. Results: The success rate of guide wire passage according to the “shape” of stricture was 88.6% (39/44) in infiltrative type, 86.1% (31/36) in nodular type, 96.4% (27/28) in mixed type, 100% (5/5) in papillary type, and 92.3% (12/13) in unclassified type (P>0.05). According to the “location” and “length”, it was 90.6% (29/32) in upper, 94.2% (49/52) in mid, and 90.6% (36/42) in lower third type (P>0.05), and 86.2% (25/29) in <1 cm, 90.9% (70/77) in 1-3 cm, and 95.0% (19/20) in >3 cm type (P>0.05), respectively. Conclusion: These results show that characteristics of malignant biliary stricture do not influence on the success rate of EBS for the palliation of MBDO and suggest that, to increase success rate of EBS, endoscopists should be familiar with standard or specialized guide wire and their handling techniques to overcome difficult guide wire passage across especially short segment, nodular, and distal stricture of the common bile duct. Background: Endoscopic biliary stenting (EBS) is accepted as an effective palliative drainage procedure for malignant bile duct obstruction (MBDO) and the prerequisites for success are selective bile duct cannulation, guide wire passage across the stricture, and accurate stent placement in the bile duct. Of these, difficult guide wire passage is a main cause of failure. Although successful guide wire passage is influenced by the endoscopist's experience of using guide wire, it may depends on the cholangiographic characteristic of stricture itself. Aim: To determine whether characteristic of stricture influence on the success rate of guide wire passage across the malignant biliary stricture. Methods: To define cholangiographic characteristic of stricture, complete review of endoscopic retrograde cholangiograms of 126 patients (59M/67F, age range 49-88, mean 67.4 years) with MBDO treated with EBS during the past 5 years was done by biliary endoscopist and abdominal radiologist. Etiology of stricture included bile duct cancer (n=74), pancreatic cancer (n=30), gallbladder cancer (n=17), and metastasis (n=5). The “Shape” of stricture was classified as infiltrating, nodular, nodular-infiltrating (mixed), and papillary (Sakamoto et al, Ann Surg 1998), the “location” as upper, mid, and lower third of the common bile duct, and the “lengh” as <1 cm, 1-3 cm, and >3cm. The success rate of guide wire passage according to the cholangiographic characteristics mentioned above was assessed and compared. Results: The success rate of guide wire passage according to the “shape” of stricture was 88.6% (39/44) in infiltrative type, 86.1% (31/36) in nodular type, 96.4% (27/28) in mixed type, 100% (5/5) in papillary type, and 92.3% (12/13) in unclassified type (P>0.05). According to the “location” and “length”, it was 90.6% (29/32) in upper, 94.2% (49/52) in mid, and 90.6% (36/42) in lower third type (P>0.05), and 86.2% (25/29) in <1 cm, 90.9% (70/77) in 1-3 cm, and 95.0% (19/20) in >3 cm type (P>0.05), respectively. Conclusion: These results show that characteristics of malignant biliary stricture do not influence on the success rate of EBS for the palliation of MBDO and suggest that, to increase success rate of EBS, endoscopists should be familiar with standard or specialized guide wire and their handling techniques to overcome difficult guide wire passage across especially short segment, nodular, and distal stricture of the common bile duct.