Pentazocine, which is known to act as an agonist at kappa opioid receptors and a weak antagonist or a partial agonist at mu receptors has shown significant anticonvulsant activity in MES test and abolition of this anticonvulsant activity by high dose but not by low dose of Naloxone. The present study was designed to compare the anticonvulsant effect of Pentazocine with standard Sodium Valproate in albino rats. An attempt was also made to determine the possible opioid receptor mechanism involved.