Anatomical variations of biceps brachii muscle pertaining to its manner of insertion are rare and seldom reported. Compression neuropathy of superficial branch of radial nerve and partial obstruction of radial artery owing their etiology to a variant insertion manner of biceps brachii is exceptionally unique. In this report, we attempt to describe an accessory tendo-aponeurotic slip of the biceps brachii which traversed across the forearm to join the medial border of extensor carpi radialis longus muscle. During its course it crossed superficial to the proximal part of radial artery and the superficial branch of radial nerve, possibly compressing them. This report not only provides a precise working knowledge to clinicians and surgeons, but also encourages further scope of detailed anatomical study of insertion variations of biceps brachii.