Splenic cysts are uncommon, with fewer than 600 cases reported in the world literature. This report concerns a case of cystic lymphangioma of the spleen, consisting of a large splenic cyst with associated multiple, small, subcapsular cysts and lymphangiectasia. The cysts are lined by endothelium, and they conform to the characteristics of dilated lymphatic channels. Lymphangioma of the spleen is thought to arise from congenital obstruction of lymphatic flow, with subsequent dilatation of lymphatic channels. The diagnosis and treatment of splenic cysts are discussed and a new classification of splenic cysts is proposed.