We present a case of an anomalous radial artery (ARA), which arose as a branch of the thoracoacromial trunk. After giving rise to the lateral thoracic artery, the ARA continued superficially through the brachium and antebrachium, terminating as the deep palmar arterial arch. This anomalous artery was found to completely replace the radial artery which normally arises from the brachial artery. Embryological considerations and possible clinical consequences are discussed.