Cognitive functions were studied in 20 previously untreated epileptics on sodium valproate monotherapy. Before start of therapy and at every 3 months interval till 9 months, cognitive functions were evaluated (modified WAIS) and serum valproic acid was estimated (FPIA) in all patients. There was progressive improvement in attention, immediate recall, intelligence and visuo spatial functions, after drug therapy but the orientation, recent and remote memory remained unaltered. None of our patients showed impairment in cognition. The improvement in congnition was apparently due to adeauate seizure control. These alterations had nocorrelation with serum levels of valproic acid