Serous microcystic adenomas or serous cystadenomas are rare and account for 1-2% of the exocrine neoplasms of the pancreas. Recently, due to the improvements in imaging techniques, they have been identified more frequently. We present the case of a patient in whom a serous microcystic adenoma, 26 cm in diameter, was found incidentally in the pancreas, the largest reported in the literature thus far. Pylorus-preserving pancreaticoduodenectomy was performed, combined with a right hemicolectomy because of the tumor localization. Despite their size, the resection of serous microcystic adenomas, even of that magnitude, is operatively efficient and should always be taken into consideration when examining therapeutic options.