The repetitive overhead use of the arm required by many sports may lead to impingement in the vulnerable avascular region of the supraspinatus and biceps tendons. The impingement syndrome may spill over at any time to involve the adjacent biceps tendon, subacromial bursa, and acromioclavicular joint and, as a continuum, with the passage of time, may eventuate in degeneration and partial, even complete thickness, rotator cuff tears later in life. Physical findings, particularly a positive impingement sign, confirm the diagnosis. In the young competing athlete, therapeutic measures consist of careful warm-up exercises, occasional rest by avoidance of the offending movement, and local modalities of ice, ultrasound, and transcutaneous stimulation along with anti-inflammatory medications. Surgical decompression achieved by resecting the coracoacromial ligament or a more definitive anterior acromioplasty may rarely be indicated.