Objective To investigate the role of endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis and treatment of adult biliary ascariasis.Methods Clinical data of 19 cases of adult biliary ascariasis diagnosed and treated with ERCP during Jan 2005 to Dec 2012 were retrospectively analyzed.Results Among the 19 adult patients with biliary ascariasis,11 were male,and the mean age was (62.7± 10.8) years.Eight cases lived in the countryside,7 cases in the integration of urban and rural area,and 4 cases in urban area.All cases had histories of eating raw fruits and vegetables.Living worms were found in 9 cases.Four cases were complicated with common bile duct stones.Petrification of residual dead worms in the common bile duct was found in 10 cases.All ascariasis and residual bodies were removed successfully by ERCP.There were no postoperative complications except for 3 cases of hyperamylasemia.Conclusions Adult biliary ascariasis commonly occurs in the elderly,and is frequently complicated with common bile duct stones.ERCP is efficacious in treating biliary ascariasis.