The ulnar forearm flap has been performed by many authors for the reconstruction of finger injuries. This article describes the refinement of the perforator anatomy based on ulnar artery and presents our clinical experience using ulnar artery perforator free flap for finger resurfacing. An anatomical study conducted in 10 cadaver forearms demonstrated the consistent origin of the ulnar perforator from the ulnar artery 40 mm proximal to the pisiform. The diameter of the artery was 0.9 mm and the average length of the perforator from the skin to the origin of ulnar artery was 20 mm. Based on this anatomic knowledge, 5 patients underwent ulnar artery perforator flap operations for finger resurfacing. All flaps survived without complication, and the patients were satisfied with the aesthetic and function outcome. The ulnar artery perforator flap is thin and pliable and provides nonhairy skin with color and texture matches. In addition, it is a simple and fast procedure with a reliable and constant blood supply. The ulnar artery perforator flap could be an alternative for the resurfacing of finger defects.