We have identified a new perforator flap located on the anterior lateral arm. Purpose: To define the anatomy of this anterior lateral arm perforator flap Method: Twelve fresh cadaver arms were dissected using 2.5x magnification loopes. The following measurements were taken of this flap: pedicle length, vessel number, vessel diameters, and flap thickness. A methylene blue injection study was used to determine the size of this pedicle flap Results: On all dissections, the pedicle originated directly from the proximal brachial artery and vein. All the pedicles had 1 artery and 2 veins. Twenty-two percent of the pedicles were intramuscularly located in the brachialis muscle. The mean pedicle length, arterial diameter, and venous diameter were 8cm, 1.5mm, and 2mm, respectively. The mean flap thickness was 1.6cm. The flap measured 10cm x 15cm. The flap was harvested within 1 hr. The donor was easily closed when < 1/3 of the arm circumference was harvested for the flap. Without tension on its pedicle, the flap rotated to reach the shoulder, axilla, and lateral breast. Conclusion: We have identified the anatomy of a new anterior lateral arm perforator flap. This flap can be potentially used as a pedicled and free flap.