OBJECTIVE: Sex differences following concussion are poorly understood. The purpose of this study was to examine whether male and female adolescent athletes with prior concussions differ regarding neurocognitive function and symptom reporting. SETTING: Community-based hockey teams. PARTICIPANTS: Participants included 615 elite hockey players 13 to 17 years old (mean = 15.5, 95% confidence interval [CI] = 15.4-15.6). There were 517 males and 98 females. Players with English as a second language, attention or learning problems, a concussion within 6 months of baseline, or suspected invalid test profiles were excluded from these analyses. DESIGN: Cross-sectional. MAIN MEASURE: Domain scores and symptom ratings from the ImPACT computerized battery. RESULTS: There were no significant neurocognitive differences between males and females with (F5,227 = 1.40, P = .227) or without (F5,376 = 1.33, P = 0.252) a prior history of concussion. Male and female athletes with a history of concussion reported higher raw symptom scores than those without a prior concussion; however, sex differences disappear when symptom scores are adjusted for known sex differences in controls (total score, F2,230 = 0.77, P = .46; Cohen d = 0.01 or domain scores (F4,227 = 1.52, P = .197; Cohen d = 0.07-0.18). CONCLUSIONS: Although those with prior concussions report more symptoms (but do not differ on neurocognition), this study does not support sex differences with cognition or symptoms in adolescent athletes with prior concussions.