BACKGROUND: Although previous research has demonstrated that patients with posttraumatic migraine (PTM) after concussion report more symptoms and cognitive deficits after injury than do those without PTM, it is not known whether these effects persist beyond the first week of injury or whether PTM predicts recovery time. PURPOSE: To determine whether PTM during the first week after injury predicts (1) cognitive impairment and symptoms in the second week after injury and (2) overall recovery time. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Participants were 138 male high school football players with a mean age of 15.96 years (SD, 1.18 years; range, 13-19 years). They were classified into 3 groups: PTM (headache, nausea, and photosensitivity or phonosensitivity), headache (headache without the other PTM symptoms), or no headache (no headache or PTM symptoms). The Immediate Post-concussion Assessment and Cognitive Test (ImPACT) was used to assess cognitive performance and symptoms at baseline, postinjury days 1-7, and postinjury days 8-14. Recovery time data were collected from medical records. RESULTS: The PTM group performed worse on verbal memory than did the headache group at 8-14 days after injury. The PTM group performed worse on visual memory, reaction time, and symptoms than did the other groups at 1-7 days and 8-14 days after injury. The PTM group was 7.3 times (95% confidence interval, 1.80-29.91) more likely to have protracted recovery (>20 days) than the no headache group and 2.6 times (95% confidence interval, 1.10-6.54) more likely than the headache group. CONCLUSION: Results suggest that PTM is associated with cognitive impairments and protracted recovery and that headache alone is not a good predictor of recovery.