In briefShoulder pain caused by impingement of subacromial tissues is a common overuse injury in swimming, especially among adolescents who may have rigorous training schedules and be skeletally immature. A case of a 14-year-old girl with swimmer's shoulder demonstrates the diagnostic work-up, which involves pertinent history, inspection, palpation, and assessment of strength, impingement, and instability. Treatment focuses on icing, relative rest, physical therapy, and modifying the swimming workout to reduce overuse and impingement.