The use of radial arteries as an arterial bypass conduit is an invasive procedure which is becoming popular among various medical centres. The greatest risk associated with harvesting the radial artery is ischaemia of the soft tissues of the hand. In this study we dissected 200 hands derived from 100 formalin-fixed cadavers in order to identify arterial patterns that will allow safe removal of the radial artery for use in bypass procedures. A complete superficial palmar arch (SPA) was found in 90% of the cases and divided into 5 types, while the remaining 10% possessed an incomplete palmar arch. Types of SPA are designated by the letter S. In type S-I (40%), the SPA is formed by anastomosis of the superficial volar branch of the radial artery to the ulnar artery. Type S-II (35%) is formed entirely of the ulnar artery. Type S-III (15%) is formed by anastomosis of the ulnar and median arteries. Type S-IV (6%) is formed by anastomosis of the ulnar, radial, and median arteries and Type S-V (4%) is formed by a branch of the deep palmar arch (DPA) communicating with the SPA.DPA was identified in all specimens and classified into three types, all designated by the letter D. Type D-I (60%) is formed by anastomosis of the deep volar branch of the radial artery and the inferior deep branch of the ulnar branch. Type D-II (30%) is formed by anastomosis of the deep volar branch of the radial artery and the superior deep branch of the ulnar artery. Type D-III (10%) is formed by anastomosis of the deep volar branch of the radial artery with both deep branches of the ulnar artery. This data could provide an important source of information for vascular surgeons harvesting radial arteries.