Abstract: In a previous paper we reported the cardiotonic effect of the glucoside B of Nerium indicum. Further studies were undertaken on the cardiovascular effects of this substance in rabbits, cats and dogs, and the following results were obtained: The glucoside B of Nerium indicum produced prompt cardiotonic action and only 10% of its action persisted 3 days after its administration. Its cat unit was found to be 0.27mg/kg. Prolongation of P—P interval and invertion of T wave were its characteristic ECG changes. After oral administration about 50% of the intake was absorbed in three hours.