Error-related negativity (ERN/Ne) is component of the event-related brain potential (ERP) associated with monitoring action and detecting errors. It is a sharp negative deflection that generally occurs from 50 –150 ms following response execution. BESA analysis and recent fMRI studies have shown that the source of this activity is a medial frontal generator, most likely involving the anterior cingulate cortex (ACC). The ACC is part of a frontostriatal circuit thought to be the neural basis of a generic error-processing system. Gehring et al. (2000, Psychological Science,) have recently observed an enhanced ERN in subjects with Obsessive-Compulsive Disorder (OCD), a finding consistent with the interpretation that OCD symptoms are related to hyper-active action and error monitoring systems in the brain and with the hypothesis that the frontostriatal circuit may be dysfunctional in patients with OCD. We extended these findings by measuring the ERN in subsyndromal undergraduates with OCD characteristics assessed with the Obsessive-Compulsive Inventory (OCI). Eighteen high-OCI subjects and 17 low-OCI subjects performed a modified Stroop task with equal emphasis placed on speed and accuracy. Response-locked ERPs from Fz, Cz and Pz revealed a frontally-maximal negativity associated with erroneous responses. Consistent with Gehring et al., the ERN was significantly larger in the high-OCI group when error trials were compared to all correct trials or to a subset of correct trials matched with error trials on reaction time. There were no performance differences between the two groups. Our results support the view that the characteristics associated with OCD are related to hyper-functioning error and action monitoring processes.