The narrow field of non-controversial indications concerning the application of digitalis glycosides is pointed out. Problems of routine digitalization of older patients not suffering from cardiac insuffiency are discussed with special regard to preparing them for operations. Up to now, from the viewpoint of anaesthesiologists no benefits of prophylactic digitalization have been found. In a retrospective computerized study, clinical hemodynamic parameters during introduction of anaesthesia have been investigated by means of anaesthetic data recorded during three years. Nondigitalized patients older than fifty years showed satisfactory cardiac functions, whereas prophylactically digitalized patients--compared with the control group--have been treated with plasma expanders earlier and at a double rate. Furthermore, higher heart frequencies and greater tendency to arrythmias were observed. Consequently, prophylactic digitalization cannot be recommended in general.