A case of cystic lymphangioma of the lesser omentum is described herein. The patient was a 46-year-old man who initially presented with an abdominal mass. Abdominal computed tomography (CT) detected an 11.6x4 cm, lobulated, contoured, low density lesion on the lesser sac. Excision of the mass, including the lesser omentum, and pyloroplasty were performed. The mass was semitranslucent and cystic, and it measured 10x9x2.5 cm in size. The external surface was smooth, but partly enclosed within adipose tissue. The oligolocular cysts contained clear and milky fluid. To our knowledge, this is the first case of lymphangioma of the lesser omentum in the Korean literature. A brief review of the literature is presented following the case report.