In 2008, the Concussion in Sport Group (CISG) published its third consensus statement and introduced 10 'modifying' factors that were presumed clinically to influence the investigation and management of concussions in sports. Young age was listed as one of the modifying factors. In some cases, these modifiers were thought to be predictive of prolonged or persistent symptoms. These same modifying factors were retained in the fourth iteration of the CISG consensus statement (2013), although mention was made of possible limitations of their efficacy. The CISG statements provided several empirical references regarding young age as a modifying factor. We reviewed the published sports concussion literature with the purpose of determining empirical studies that support or refute the inclusion of young age as a modifier of concussive injury in sports. We performed a systematic review of the PubMed database utilizing the keywords concussion, sports, mild traumatic brain injury, youth, adolescents, and children. English language studies were extracted by the authors and summarized for review. Multiple empirical studies were found indicating that younger athletes may take longer to recover from a sports-related concussion (SRC) than their older peers. However, studies did not indicate that younger athletes were at more risk for prolonged recovery (>4 wk). Empirical evidence supports the inclusion of young age as a modifying factor in sports concussion. However, the difference in recovery time seems relatively small (a few days) and young age does not predict prolonged recovery (>4 wk). The findings support the inclusion of young age as a specific modifier in the treatment of SRC and have implications for the clinical management of this common injury.