Venous leiomyosarcomas are rare tumors, generally originating from the inferior vena cava. Only two cases of ovarian vein leiomyosarcoma have been reported thus far. Herein we report the case of a 50-year-old woman with a leiomyosarcoma of the right ovarian vein. The patient underwent radical en bloc extirpation of the tumor followed by radiation therapy. The clinicopathologic features and treatment are discussed.