OBJECTIVE: To determine whether slow processing speed is associated with risk of sport-related concussion. DESIGN: We conducted a retrospective cohort study using computerized neurocognitive assessments (Immediate Post-concussion Assessment and Cognitive Testing [ImPACT]) from the Massachusetts Concussion Management Coalition. Slow processing speed was defined as 2 SD below the sample mean (n = 131) and fast processing speed as 2 SD above the sample mean (n = 259). We used a binary logistic regression model to determine the odds of sustaining a concussion with our main predictor being processing speed (high or low) adjusted for the effects of age, sex, and prior number of concussions. SETTING: Massachusetts Concussion Management Coalition, Institutional care. PARTICIPANTS: Three hundred ninety junior high soccer players ages 10 to 15 with a baseline score for ImPACT. INDEPENDENT VARIABLES: Processing Speed. MAIN OUTCOME MEASURES: Risk of sustaining a concussion. RESULTS: Those with slow processing speed had a visual motor composite score of =19.92, those with fast-processing speed had a score of >/=46.20. Athletes with slow processing speed were younger (13 vs 14 years; P < 0.001) and more likely to be male (57% vs 49%; P = 0.014). After adjusting for the effects of age, sex, and prior concussions, there was no significant difference in the odds of sustaining a concussion between groups (aOR 1.01; 95% CI, 0.99-1.04). CONCLUSIONS: Despite previous research showing that slow processing speed is a risk factor for musculoskeletal injuries during sports, our study suggests that processing speed is not associated with the risk of sustaining a concussion among junior high school soccer players.