Objective: To examine patient and injury factors that may predict quality of life (QoL) and symptom duration after concussion. Design: Prospective, longitudinal. Settings: Six children's hospital-based medical centers and 9 secondary school athletic training facilities. Patients: Pediatric patients (8-18 years) were enrolled as part of the Sport Concussion Outcomes in Pediatrics (SCOPE) study during their initial visit for a diagnosis of sport-related concussion. Interventions: Patients completed a medical history, the Postconcussion Symptom Inventory (PCSI), and Patient-Reported Outcomes Measurement Information System Pediatric Profile-25 (PROMIS-PP). Main Outcome Measures: Eight predictor variables [age, sex, assessment time, loss of consciousness, amnesia and history of concussion, migraines, or attention-deficit hyperactivity disorder or (ADHD)] were assessed using regression models constructed for each dependent variable. Results: A total of 244 patients (15.1 6 2.1 years, 41% female) were enrolled (mean 5 5 6 3 days after concussion; range 5 1-14 days). Female sex, later initial assessment, and presence of amnesia were associated with lower QoL scores on several domains, whereas loss of consciousness was associated with higher QoL for fatigue. A history of migraines was associated with lower peer relationship QoL. Patients who subsequently developed persisting symptoms had lower mobility scores and higher anxiety, depressive symptom, fatigue, and pain interference scores. Conclusions: Female sex, later clinic presentation, and amnesia were associated with a lower QoL related to mobility, anxiety, depressive symptoms, fatigue, and pain interference. Interestingly, previous concussion and preinjury ADHD diagnosis did not negatively impact postinjury QoL at the initial visit. Future studies should assess the influence of these factors on QoL at later postinjury time points using a concussion-specific outcomes instrument.