Reports of normal Continuous Performance Test (CPT) accuracy in patients with temporal lobe epilepsy (TLE) stand in contrast to a demonstration of nonspecific absolute reaction time (RT) deficits in this population. In this study, we examined CPT data from a TLE sample for potential RT deficits across three consecutive blocks of time during the vigil. Seventeen patients with medically intractable epilepsy of temporal lobe origin and 17 healthy volunteers participated. The Conners CPT was used to assess sustained attention over a 14-min vigil. There were no significant group differences in accuracy. There was, however, a significant interaction between groups and time intervals, with disproportionate RT increases for patients at the end of the vigil. These findings are consistent with a report of nonspecific RT deficits in TLE despite normal accuracy scores, and further indicate impaired RT performance over time.