Objective:This study aims to determine the yield of EUS in patients with common bile duct (CBD) dilation and normal liver function tests (LFTs).Materials and Methods:Between October 2000 and December 2016, all patients referred for EUS for unexplained CBD dilatation (CBD ≥7 mm), with normal aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and bilirubin and no history of sphincterotomy, were eligible. Linear-array EUS was performed by one of the two experienced endosonographers. Data were extracted from a prospectively maintained database.Results:Of 29,920 upper gastrointestinal EUS procedures performed, 840/29,920 (3%) were for unexplained CBD dilation. Of 840 patients, 199 (24%) had normal LFTs, 99% were Caucasian, 46% had biliary-type abdominal pain, and 41% were postcholecystectomy. EUS diagnosed choledocholithiasis (CDL) or sludge in 18/199 (9%) patients (7/18 had CBD sludge only). No other pathology was diagnosed. Of 18 CDL patients, 15 (83%) had an intact gallbladder, and all 15 patients had cholelithiasis. The frequency of CDL or sludge in postcholecystectomy patients was only 3.7% (3/82); none of these patients were younger than 69 years of age. Regression analyses showed no associations between EUS diagnosis of CDL or sludge and biliary-type abdominal pain, other symptoms, sex, or race. Each additional year of age was associated with an increase in the risk of CDL or sludge by a factor of 1.05 (odds ratio: 1.05; P = 0.034).Summary:In patients with CBD dilation and normal LFTs, the only significant pathology identified is CBD stones or sludge (almost exclusively in elderly patients with cholelithiasis).Conclusion:EUS should be avoided in patients with dilated bile ducts and normal LFTs, especially if under 65 years of age and postcholecystectomy.