ABSTRACT
The median artery is a main artery that supplies hand in embryonic period. When the radial and ulnar arteries are well developed, the median artery becomes smaller and soon disappeared. In order to find the incidence of persistant median artery in Thais, we study 266 upper extremities in our Department, 133 of right sides and 133 of left sides. The persistant median artery is found in 22 extremities, or 8%. Further studies reveal that, 77% of median artery are the branch of ulnar artery, 9% of common interosseous artery and 14% of brachial artery. 91% of median artery accompany the median nerve throughout forearm, while 9% traveling superficially in the same plane as supper veins. All of median artery end by joining superficial palmar arch. 95% pass deep to flexor retinaculum, only 5% pass superficial to this retinaculum before joining superficial palmar arch.