Objective:To evaluate the value of Cook MOB-15 system in guiding wire insertion during endoscopic retrograde cholangiopancreatography (ERCP). Methods: The clinical data of 51 patients who received Cook MOB-15 system-guided wire insertion during ERCP between Jan. 2005 to Dec. 2007 were retrospectively analyzed. Forty patients who received conventional ERCP catheter for malignant jaundice between Jan. 2002 and Dec. 2004 were taken as control. The successful insertion rates were compared between the 2 groups. Results: The successful insertion rate was 90.2% (46/51) in the Cook MOB-15 system group and 72.5% (29/40) in the conventional group; there was significant difference between the 2 groups (P<0.05). Conclusion: The Cook MOB-15 system can significantly raise the successful insertion rate in ERCP.