Adenomyoma is a rare non-neoplastic lesion of the biliary tract. Here we report on three cases of adenomyoma; one located in the ampulla of Vater and two located in the common bile duct. Although preoperative endoscopic and radiological evaluations could not determine whether lesions were benign or malignant, intra-operative frozen section histologic examinations aided the differential diagnosis. Microscopic features of a lobular gland architecture with basally located nuclei and the absence of desmoplastic stromal reaction were found to be characteristic in frozen and paraffin sections.