Vascular anomaly is a general term that includes all vascular malformations, vascular tumors, and other congenital vascular defects. Vascular malformation is the most common term, and it describes blood vessels that are abnormally formed at birth. Vascular malformations can develop in any part of the body. The most common location is in the lower extremities. Vascular malformations involve arteries, veins, or lymphatic vessels, or a combination of these. Our patient was a 22-year-old man with an arteriovenous malformation in his left forearm. He was admitted due to increased pain and swelling on his left forearm over the previous 9 months. He had 1 arterial feeder derived from the ulnar artery and 2 venous drainage systems at the magnetic resonance angiography. We used indocyanine green fluorescence angiography to assess the arteriovenous malformation during surgery. We found that it was a very useful and unique technique for assessing the anomalies of the vascular anatomy and eradicating the nidus of the arteriovenous malformation. It could prove to be very helpful in avoiding significant blood loss during surgery.