Objective: To investigate sex differences in neurocognitive function and post-concussion symptom scores among concussed high-school and collegiate athletes.Method: A prospective repeated-measures design was used to compare baseline and post-concussion neurocognitive performance and concussion symptoms. Independent variables were sex (male, female) and time (baseline and 2 days, 7 days, 14 days post-injury). The dependent variables were the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) cognitive composite scores (i.e., verbal memory, visual memory, motor processing speed, reaction time) and total concussion symptoms. Ninety-four concussed athletes with a baseline ImPACT test completed a follow-up ImPACT test at 2-, 7- and 14-day post-concussion. Repeated-measures analysis of variance (ANOVA)s were conducted on each cognitive composite score. Results: Results revealed a significant sex difference in visual memory composite scores (F(3, 32) ¼ 3.53, p ¼ .03). Female athletes demonstrated cognitive impairments 14 days post-concussion compared with male athletes who demonstrated a return to baseline at 14 days postinjury. The results also indicated significant sex differences on total concussion symptoms at 7 days post-concussion (F(3, 32) ¼ 5.75, p ¼ .003), as female athletes reported a higher total number of concussion symptoms than males. There were no other significant sex differences on the other neurocognitive composite scores. Conclusion: Female athletes at both high-school and collegiate levels may exhibit a more prolonged cognitive recovery and appear to exhibit longlasting concussion symptoms than males.