Isoproterenol is a B-adrenergic stimulant. The ability of isoproterenol To induce histological alterations of the heart resembling severe myocarditis had been noted.Verapamil is a calcium channel blocker, several trials have been made to reduce the cardiotoxic effects of isoproterenol through a prelimenary injection of Verapamil the present work is aiming at clarifying the possible protective effect of Verapamil againt isoproterenol induced Myocardial damage in Albino rats . It was found that verapamil injection I.P. 10 mins prior to isoproterenol S.C. injection had a protective effect on the rat myocardium as detected by histological examination.