A variety of cerebral vascular anomalies are widely applied, however anomalies of the middle cerebral artery (MCA) are relatively infrequent. The duplicated MCA (DMCA) is a MCA anomaly. Aneurysm arising from the origin of the DMCA is rare. Cerebral angiography in a 61-year-old female demonstrated a small (about 3 mm) saccular aneurysm located at the origin of the DMCA in the anterior direction. Considering the unusual location, the lesion was treated, regardless of the size. Aneurysmal characteristics of a broad neck and small size limited the endovascular approach, necessitating open surgery. Her postoperative course was uneventful and postoperative angiography showed complete obliteration of the aneurysm. The patient was discharged without neurologic deficit.