We investigated the digitalis like potentialities of judaicin in rats. Both the pharmacologie and the toxic actions of judaicin and digoxin were studied in respect to. the cardiac response. The pharmacological action as well as the cardiotoxic action of both drugs were electrocardiographically parallel. Both drugs caused a prolongation in the P–R interval and enforcement of the cardiac contractility. Further investigations are required for completing the picture of the pharmacological action of judaicin.