Magnetic resonance imaging has proven to be useful in the assessment of rotator cuff injuries. Improvements in magnetic resonance techniques, including fast spin-echo imaging and fat saturation, have facilitated demonstration of tendinous abnormalities of the rotator cuff. Rotator cuff disease is multifactorial. Primary impingement within the coracoacromial arch, degeneration of the rotator cuff tendons, trauma, and glenohumeral instability may be contributing factors. Shoulder pain in athletes can be related to acute myotendinous and muscle injuries, which can be easily detected using magnetic resonance imaging.