The goal of this study was to investigate the vascular supply of the distal dorsal forearm and the feasibility of using a local skin flap based on perforating vessels of the anterior interosseous artery (AIA) to reconstruct the dorsal aspect of the hand. The results of anatomic studies on 71 adult, fresh-frozen cadaveric upper extremities indicate that a new flap can be designed based on a cutaneous branch of the AIA. The AIA runs along the volar surface of the anterior interosseous membrane. At the proximal border of the pronator quadratus muscle it gives off a dorsal septocutaneous branch (DSCB) that pierces the interosseous membrane and supplies the extensor muscles of the thumb and the skin of the distal two-thirds of the dorsal forearm. The average artery diameter at the origin of the DSCB was 1.1 +/- 0.2 mm (mean +/- standard error of mean). The mean pedicle length was 3.1 +/- 0.6 cm. The pedicle could be extended to 12.4 +/- 0.9 cm if the entire AIA was included. Based on dye injection studies, the smallest skin paddle that could be supported by this vessel ranged from 5 x 9 cm to 8 x 15 cm. The flap can be configured as an island vascular flap based on the DSCB or AIA, a distally based flap, a free flap, a fascial flap, or a composite flap including muscle, bone, nerve, and skin.