The axillary nerve arises from the posterior cord and passes through the quadrilateral space before dividing into anterior and posterior branches. Because of its short length and relative fixation points, the nerve is vulnerable to stretch. Most of isolated axillary nerve injuries related to sports are associated with skiing and football. Nerve damage may be caused by dislocation of the shoulder, direct blow, or following common sports medicine shoulder surgical procedures. Chronic compression may occur at the quadrilateral space in throwing athletes. The condition may be asymptomatic as normal shoulder range of motion is possible if the suprascapular nerve and rotator cuff muscles are intact. EMG/NCV studies should be done early to obtain a baseline for later comparison. Most axillary injuries following shoulder dislocation recover, at least partially, within 3–6 months. Surgery is recommended if no return of function has occurred by 4–6 months, and results deteriorate if surgery is delayed 9–12 months. There is a debate regarding whether nerve graft or nerve transfer using the long head of triceps motor nerve generates better functional outcome. Because the donor nerve is much closer to the target muscle, better motor recovery can be expected after delayed repair using nerve transfer. Restoration of deltoid function by trapezius transfer was described principally in old cases of upper brachial plexus injury with concurrent involvement of the axillary and suprascapular nerves. Best results are obtained with the combined reconstruction of the deltoid and infraspinatus using the upper and lower trapezius.