Objective: This study investigated the clinical utility of the Standardized Assessment of Concussion (SAC) in detecting concussion in athletes. Method: Athletic trainers administered the SAC to 568 nonconcussed high school and college football players prior to the 1995 and 1996 football seasons. Thirty-three of these players experienced concussion and were tested immediately following injury; 28 of the 33 underwent additional follow-up testing 48 hours after the injury. Results: Concussed players scored significantly below nonconcussed controls on all SAC measures and significantly below their own pre-injury baseline performance. Follow-up testing documented return to preinjury baseline. Conclusion: These findings support the SAC's effectiveness in detecting concussion and tracking recovery in order to determine a player's fitness to return to play.