Anatomical variations in the formation of brachial plexus and its terminal branches have been reported in the literature. During the routine dissection of embalmed adult cadavers in the Institute of Anatomy, MMC, Madurai, a rare variation in the mode of termination of the posterior cord of the brachial plexus was noted. The posterior cord was terminating into two divisions, and the radial nerve was formed by the union of those divisions and the axillary nerve was arising from one of those divisions. The clinical implications of this variation are discussed.
