Considerable progress has been made in the medical treatment of chronic heart failure. A large number of patients with NYHA class II and III heart disease can be improved to class I and II. Treatment is maintained on an outpatient basis in order to prevent episodes of acute failure, while avoiding the adverse effects of drugs at high doses or in combination. Diuretics are still the drug class most frequently prescribed, especially loop diuretics (furosemide) which have the advantage of being able to be used in patients with renal failure. Aldosterone antagonists have the pathophysiological value of reducing the development of myocardial fibrosis. Digitalis alkaloids have a positive inotropic effect, which is even observed in the presence of sinus rhythm and which is associated with slowing of the heart rate in tachyarrhythmias. Angiotensin converting enzyme inhibitors are among the most recently used drugs. They decrease the left ventricular post-load and prevent activation of the renin-angiotensin-aldosterone system. Phosphodiesterase inhibitors cannot be administered orally in the long-term and are therefore not suitable for outpatient treatment. However, they are very effective by intravenous injection during the acute phase of heart failure and cardiogenic shock in hospital.