Concussion is a common injury during childhood and adolescence. For many, symptoms resolve quickly but up to a third experience persistent symptoms. Appropriate management after injury is key to improving outcomes and reducing the risk of symptom exacerbation. As care is usually provided outside of a hospital setting, clear guidelines for managing the condition are crucial. Evidence-based guidelines for children/adolescents have not yet been developed due to a lack of high-quality studies. We will fill this gap by undertaking a prospective longitudinal study of concussion recovery from the acute post-injury period to 12 months in 5- to 17-year-olds across three groups: Māori, Pacific and non-Māori non-Pacific. The study will provide detailed understanding of acute symptoms, recovery and predictors of poor long-term outcomes from concussion in children and adolescents. The findings will form the basis of future evidence-based guidelines for clinicians and families, to appropriately manage concussion and improve outcomes.