This is a case report on the surgical treatment of orbital hemangiopericytoma. The patient initially underwent an attempted excision of the tumor with significant hemorrhage elsewhere, which precluded its complete excision. Due to continued growth and pain, the patient underwent percutaneous embolization with Onyx-18 under fluoroscopic radiographic guidance. The patient continued to have pain, progressive enlargement of the tumor, and underwent surgical excision. The excision was noted to have minimal bleeding and was relatively easy to dissect and excise compared with the typical hemangiopericytoma. Embolization with Onyx-18 may be a useful preoperative treatment option for hemangiopericytomas and other vascular lesions of the orbit, and elsewhere.