Although Mirizzi syndrome was first described more than a hundred years ago, pre-surgical diagnosis conti- nues to pose a challenge. This syndrome is usually found during surgery. For that reason it has the potential for making the surgical procedure longer and for the development of complications such as fistula and biliary duct lesions. None of the procedures for diagnosis of the syndrome (including ERCP, CT, RNM, etc.) are ideal because of false negative results and the risks involved. This paper presents the cases of two patients who were diagnosed with Mirizzi syndrome with endoscopic ultrasound (EUS), and also presents a review of the literature.