Two cases of retroperitoneal cystic lymphangioma (CL) are presented; the current literature on this rare, benign neoplasm of the lymphatic system is reviewed. This tumor consists of various numbers of cyst-like cavities filled with a serous, serosanguineous or chylous fluid. The histogenesis of CL is still uncertain. Most commonly CL occurs in the neck and in the axillary region, whereas it is rare in the retroperitoneum. Although retroperitoneal CL is a benign lesion, it may cause significant morbidity due to its large size, and its often invasive character with a strong tendency to secondary infection. The treatment of choice is surgical excision.