Acute heart failure (AHF) is defined as the rapid onset of symptoms and signs secondary to abnormal heart function which may occur with or without previous cardiac disease. Diagnosis and classification of severity are primarily based on clinical findings. The conditions leading to and reasons for acute heart failure which require specific therapeutic interventions should always be taken into consideration. Immediate goals in the guideline-oriented treatment of AHF are to improve the patient's symptoms and stabilize the hemodynamic condition. Medical therapy - besides oxygen supply - consists of the application of vasodilators, diuretics, and inotropes (especially dobutamine) depending both on the patient's clinical state and hemodynamic parameters. In the presence of ongoing signs of hypoxia, non-invasive ventilation has to be considered early. Bradycardia in AHF patients should initially be treated with atropine; a temporal pacemaker has to be inserted if no response is achieved by medical therapy. Ventricular fibrillation and tachycardia require immediate cardioversion.