Sinonasal hemangiopericytoma is a rare sinonasal mesenchymal tumor, and is considered different from other reported hemangiopericytomas. A 37-year-old man presented with intermittent left epistaxis for three days. Rhinoscopic examination revealed a smooth red mass in the left middle nasal meatus. A pathology report of the biopsy specimen showed sinonasal hemangiopericytoma. Magnetic resonance imaging demonstrated the tumor had eroded the posterior nasal septum, involved the bilateral posterior ethmoid sinuses, and obstructed the ostium of the left maxillary sinus causing left maxillary sinusitis. After transarterial embolization, the tumor was endoscopically excised with a microdebrider. The postoperative course was uneventful and epistaxis did not recur during the following two years. Follow-up magnetic resonance imaging did not show any tumor recurrence, although the bilateral maxillary sinusitis remained. Nevertheless, the patient should be followed regularly to exclude the possibility of recurrence or metastasis.