OBJECTIVES: This cohort study was conducted to examine patterns of symptom reporting in concussed athletes in two different testing environments. DESIGN: A prospective cohort study was conducted with repeated measures. METHODS: Self-reported symptoms collected by team athletic trainers using the ImPACT Post-Concussion Scale (PCS) were compared to symptoms collected in a confidential setting using structured interviews for depression and anxiety. Ratings were scaled to match scoring of the PCS and categorized into symptom-domains. Scores collected 2 days post-concussion were compared across different rating scales. Confidential self-report scores approximately 9 days post-concussion in cleared athletes were compared to PCS scores collected during return-to-play decisions. Finally, confidential self-report scores collected 9 days post-concussion were compared between cleared and not cleared athletes. RESULTS: Athletes self-reported significantly fewer symptoms to team athletic trainers using the ImPACT test compared to self-reported symptoms collected in a confidential setting during the acute phase of concussion using standard psychiatric interviews. Athletes cleared to play continued to underreport symptoms 9 days post-concussion, particularly psychiatric symptoms. Finally, cleared athletes self-reported similar magnitude of symptoms than non-cleared athletes 9 days post-concussion in confidential research setting. CONCLUSIONS: The systematic underreporting of post-concussion symptoms may represent motivated behavior or differences in self-reporting data acquisition. By underreporting symptoms, many cleared athletes are still symptomatic over 1-week post-concussion. This study highlights the need for objective measures for somatic and psychiatric symptoms.