BACKGROUND: The purpose of this study was to conduct a systematic review of the literature to evaluate the characteristics of injury and treatment outcomes of rotator cuff tears in young patients. METHODS: A systematic electronic search was performed for clinical studies evaluating rotator cuff tears in patients younger than 40 years with special emphasis on reporting of injury characteristics and treatment outcomes with a minimum 1-year follow-up. RESULTS: Twelve studies (involving 336 patients) met inclusion criteria. The mean age of the patients was 28 years (range, 16-40 years), with a mean follow-up of 39 months. There were 2 distinct subgroups. The majority of studies (7 of 10) showed that patients typically had a full-thickness tear with an acute traumatic etiology. However, within the subgroup of elite throwers, 5 of 6 studies demonstrated a majority of tears that were partial thickness stemming from chronic overuse. Rotator cuff repair improved pain and strength in almost all studies reporting on these parameters. Eighty-seven percent of patients reported they were satisfied. However, all studies examining elite throwers showed significant difficulty in returning to play (25%-97%). CONCLUSIONS: In young patients with rotator cuff tears, there are 2 primary groups. (1) A majority group with rotator cuff tears of traumatic origin responded well to both arthroscopic and open rotator cuff repair in terms of pain relief and self-reported outcomes postoperatively. These patients reported high levels of satisfaction and return to preinjury level of play. (2) A unique subpopulation composed of elite throwers had improved outcomes but suboptimal return to play