The pronator quadratus is the principal muscle responsible for pronation of forearm, helped by the pronator teres. To study the innervation of the pronator teres, eighteen forearms from a formol fixed corpses were dissected and the relationship of the median nerve to the pronator teres was examined. The elbow articular line was used as reference point. In all cases the most branches of the median nerve to the pronator teres began in the arm distal third part, whereas the most branches penetrated at the distal half of the forearm proximal third part (75% in right upper limb and 75.8% in left upper limb). The treatment of pronator syndrome could be making easier with the knowledge of the anatomical distribution of nerves