It is reported the first observation of cardiogenic shock without delay, in a leukemic patient during a first injection of Rubidazone (22050 RP) which is recognized so far, as one of the least cardiotoxic anthracyclines. It has been concluded: --anthracyclines, beside the risk of a progressive cardiomyopathy which is related to the dose and very well known, can induce immediate cardiac injuries, which cannot be predicted yet; --the perfect myocardial protector is still to be discovered; --in this case, beta-adrenergic stimulators appeared to be able to control the cardiotoxic effect of Rubidazone; --the last fact could be considered in the decision to maintain the treatment when such an injury occurs during a chemotherapy or when it seems absolutely necessary to use such a drug.