BACKGROUND AND OBJECTIVES: The brachial plexus is a complex network of nerves that innervates the upper limbs & since its origin in the neck throughout its course in the axillary region. It also has close relationship to important anatomic structures what makes it an easy target of a sort of variations and provides its clinical and surgical importance. The purpose of the present study was to describe the brachial plexus anatomical variations in origin and respective branches. METHODS: After approval , Thirty adult cadavers separated into sex had their brachial plexuses evaluated. The origins of the dorsal scapular, long thoracic, suprascapular, subscapular, thoracodorsal, medial pectoral and lateral pectoral nerves were studied along with the origins of the phrenic and accessory phrenic nerves. Variations of the trunks, divisions , cords & origin of terminal branches were also studied. RESULTS: Our results showed that the phrenic nerve had a complete origin from the plexus in 20% of the cases. In this way, a lesion of the brachial plexus roots could result in diaphragm palsy. The long thoracic nerve pierced the scalenus medius muscle in 64% of our cases. Another observation was that the posterior cord was formed by the posterior divisions of the superior and middle trunks in 10% plexuses. In these cases, the axillary and the radial nerves may not receive fibers from C7 and C8, as usually described. CONCLUSIONS: The plexuses studied did not show that sex or side of the body had much ( if any ) influence upon the presence of variations. An attempt has been made to know the possible variations of the brachial plexus as it is important for anaesthesiologist , Surgeons , Radiologists & Orthopaedicians to have knowledge of the variations & to be kept in mind, during anesthetic and surgical procedures.