There is a highly dependable free flap donor site of moderate size on the posterolateral aspect of the distal upper arm. The area is supplied by the posterior radial collateral artery, a direct continuation of the profunda brachii. The flap area is supplied by a direct cutaneous nerve. It can be raised on its own, with underlying tendon, with bone, or with fascia only. This article describes our findings in 32 cadaver dissections and in 23 clinical cases.