P300 event related potential was done in 23 chronic epileptics (12M, 11F) to assess subclinical cognitive impairment. No patient had any obvious neurological abnormality or brain damage. All had normal CT Scans and a mini mental scale score of at least 25. Neuropsychological evaluation done included Bender Gestalt test, Bhatia Battery, Wecshler Memory scale. P 300 event related potential was determined using 'Odd ball paradigm'. P300 latency was significantly increased in chronic epileptics (PCO < 001) compared to controls. There was no relation between P300 latency and amplitude with seizure onset, duration frequency. Nor was there any association between the three neuropsychological parameters and P 300 latency. We conclude subclinical cognitivedysfunction is common in epileptics and P300 event related potential could serve as a marker of cognitive impairment.