A double-blind placebo-controlled between-patient study was carried out to assess the effects of oxiracetam (CGP 21690E) on memory function in patients with epilepsy. During a 12-week period, either oxiracetam (800 mg t.i.d.) or placebo was given to 30 patients. Twenty-four of the patients had a partial epilepsy. Most patients were on monotherapy carbamazepine. Effect of oxiracetam on memory and related cognitive functions were assessed, using a computerized neuropsychological testing method, while concomitant electrophysiological changes were investigated with routine EEG registration, power spectrum analysis and auditory evoked event-related potentials (P3OO). Subjective evaluation of well-being was quantified with a mood rating scale. The results did not show any meaningful changes in memory function. This finding is in line with the subjective patient reports and the P3OO measures.