Mature cystic teratoma of the ovary is the most common ovarian tumor. Malignant transformation of this neoplasm is rare and is mostly represented by squamous carcinoma. Less frequently, malignant transformation is represented by a sarcoma. To date, only 5 cases of angiosarcoma arising in a mature cystic teratoma of the ovary have been reported. Herein, we report the clinicopathologic features of one such case. A review of the literature is also presented.