The aim of this study was to determine the possible effect of propranolol, a beta-adrenoceptor blocker, on maximal electroshock seizures (MES) in mice. It was found that doses of 5, 10 and 20 mg/kg propranolol caused an increase in the convulsion threshold of maximal electroshock seizures (MES) proportional to the dose and, that the mode of the anticonvulsant action of propranolol used doses in this study is related to membrane stabilization.