Variations in the formation of brachial plexus are common and have been reported by several investigators in relation to origin of roots, trunks, cords, divisions and branches. The nerves of the extremities are especially vulnerable to injury because of their long course and superficial distribution. The basic anatomy of median and ulnar nerves in the upper limb is well described in the textbooks. Previously, an ample amount of work has been done upon the communications between the median and ulnar nerves in the forearm and hand. In the present case, an unreported pattern was seen where whole of the ulnar nerve was arising from the median nerve in the arm during routine under graduate dissections, in left upper limb of a 60 year old male. Its phylogeny and clinical implications are discussed in detail. A lack of awareness of variations might complicate surgical repair and may cause ineffective nerve blockade.