Biliary endoscopic ultrasonography (EUS), even if complex and difficult to interpret, can depict with great accuracy the normal anatomy and abnormalities of this region. In case of choledocholithiasis, EUS has the unique ability to directly visualize the cause of biliary obstruction and to evaluate and integrate ductal abnormalities. For these tasks EUS is superior to conventional ultrasonography (US), computed tomography (CT) and also to new imaging techniques such as magnetic resonance cholangiography. The aim of this review is to provide an overview of the most significant EUS findings in choledocholithiasis together with the results of EUS in terms of diagnostic accuracy and cost-effectiveness. The role of EUS in the diagnosis of bile duct stones is therefore highlighted.