Anomalies of the brachial plexus have previously been described in the literature. The coracobrachialis muscle is typically innervated by the musculocutaneous nerve. During a gross anatomy dissection we found that the coracobrachialis muscle was innervated by a branch from the lateral root of the median nerve. Knowledge of the anatomical variations of the peripheral nervous system is important in interpreting unusual clinical presentations. This report will assist clinicians and surgeons by pointing out anatomical anomalies associated with the musculocutaneous nerve, the median nerve and their branches to the anterior compartment muscles of the upper arm.