The effect of the new positive inotropic and vasodilatator bipyridine-derivate Amrinon on catecholamine-refractive heart insufficiency in septic shock is described. A bolus dose of 1 mg/kg b.w., followed by continuous infusion of Amrinon 10 micrograms/kg b.w./min improved the haemodynamic parameters of all seven patients. The severe tachycardia before therapy was diminished more than 30%, the blood-pressure increased about 25-30%. RAP, PAP and PCWP showed a diminution of 35-45%. The cardiac output increased nearly 100% under therapy. All patients had IPPV with high inspiratory oxygen concentration, with inversed-ratio-ventilation and high positive end-expiratory pressure. Under Amrinon-therapy the initial pulmonary insufficiency diminished. The oliguria/anuria existing before Amrinon-therapy was improved also. Amrinon was given over 24-36 hours, the total dose was between 800 and 1440 mg. Six of the seven patients survived their severe illness; one patient died of pulmonary embolism, confirmed by autopsy, four weeks after Amrinon-therapy.