Rupture of the deltoid is a rare injury and has been reported most frequently in the elderly. It has been well recognized in association with acute or chronic massive rotator cuff tears. Spontaneous dehiscence of a deltoid repair following open cuff repairs is also well documented. A traumatic rupture of this muscle in the elderly has been attributed to weakening of this muscle from aging. 5 Repeated steroid injections for rotator cuff tendinitis may also predispose one to atraumatic deltoid tears. A traumatic rupture of the deltoid has been reported to be caused by a seatbelt during a road traffic accident in a middle-aged patient. This injury is rare in the young. It has been described in a 31-year-old bowler where the deltoid was detached from the posterolateral corner of the acromion. 1 We report a young male who sustained an anterior deltoid tear after a pull-up during military training.