Ovarian hemangiomas are benign and rare tumors of female genital tract with less than 60 reported cases in the literature. A 38- yr- old woman was admitted to Be'sat Hospital, Tehran, Iran in 2012, due to severe abdominal pain. Ultrasound evaluation revealed a 6 cm left ovarian cystic mass and serum tumor markers were normal. Then, left salpingo-oophorectomy was performed for the patient. Microscopic examination revealed a follicular cyst and an incidental cavernous hemangioma consisting thin-walled vascular channels filled with blood that lined with flatten endothelial cells. In IHC staining strong immunoreactivity for CD31 and CD34 were seen, finally, the diagnosis of primary ovarian hemangioma, cavernous-type was made. The clinicopathologic presentation of this unusual benign tumor is discussed.