Obsessive-compulsive disorder (OCD) is associated with hyperactivity of brain structures involved in performance monitoring. It has been proposed that this pathophysiology results in the generation of inappropriate or excessive internal error signals, giving rise to the characteristic symptoms of OCD. We measured an electrophysiological correlate of performance monitoring, error-related negativity (ERN), to study whether OCD patients exhibit enhanced brain activity associated with errors and negative performance feedback. We found that OCD patients (n=16) and healthy control participants (n=16) did not differ in the amplitude of the ERN associated with errors and negative feedback in a probabilistic learning task. The discrepancy between these results and the results from previous studies is discussed.