We report a very rare case of jejunal lymphangioma. A 16-year-old male sustained injuries to abdominal internal organs in a traffic accident. During emergency operation, a cystic tumor was incidentally detected in the jejunum and adjoining mesenterium and treated by segmental resection of the jejunum. The cystic tumor (5.0 x 7.0 cm) was multilocular and demonstrated to be a cavernous lymphangioma by histopathological examination. The pathology, diagnosis, and treatment of this disease described in the literature are reported.