Mild traumatic brain injuries (mTBIs) that result from participation in sports are a major public health issue affecting 1.6-3.8 million individuals annually. The injury has been postulated as transient and void of long-term consequences when rapidly diagnosed and properly managed. Emerging evidence, however, has suggested an increased risk for late life cognitive dysfunction in those with previous injuries. The purpose of this investigation was to evaluate young adults with and without a history of concussion using a standard clinical assessment and highly sensitive electrophysiological measures for persistent changes in cognitive functioning.Ninety participants (19.7+\- 1.3 years; 44 without mTBI and 46 with previous mTBI) were evaluated using the ImPACT and event-related brain potentials (ERPs) that were recorded during a three-stimulus oddball task. Those with a history of concussion reported an average of 3.4 years post-injury. No significant differences were found between groups on the ImPACT. Significant decrements in the N2 and P3b amplitudes of the stimulus-locked ERP were noted for those with a history relative to those without a history of concussion. Although the previously concussed participants performed equal to those without injury on the clinical cognitive assessment, these findings support the notion that sport mTBI can no longer be thought of as a transient injury resulting in short-lived neurological impairment. It is not clear if these persistent deficits will manifest into clinical pathologies later in life.