Angiosarcoma is a rare malignant endothelial cell tumor. Few reports of primary orbital angiosarcoma exist in the literature. A 46-year-old woman had a 3-month history of progressive diplopia and right-sided exophthalmos. Magnetic resonance imaging showed a right intraconal mass, consistent with a cavernous hemangioma. Ultrasound examination showed a isolated mass with moderate vascularity, consistent with a metastatic lesion. Subtotal excision through a lateral orbitotomy was performed. Tissue was stained with hematoxylineosin, periodic acid-Schiff, and immunohistochemical stains for factor-VIII-related antigen and Ulex europaeus agglutinin I lectin. Lateral orbitotomy biopsy specimens showed an angiosarcoma, similar to a primary breast angiosarcoma that had been resected 2 years previously. The patient initially underwent orbital exenteration for her only known metastasis. Despite a multidisciplinary and aggressive approach to this tumor, the tumor recurred, and the patient died.