The costs of different classes of acute HF (AHF) are not known.AHF patients (N=620) were divided in a national, prospective, observational study into five clinical classes: cardiogenic shock, pulmonary oedema, congestive HF, hypertensive HF, and right HF. Index episode and 6-month readmissions were assessed and hospitalization costs were evaluated.The length of index episode, ICU/CCU stay and costs of index episode and cumulative 6-month costs differed significantly between the clinical classes. The highest cumulative 6-month hospitalization costs, 25,963 (15,053–44778) € (mean, 95% confidence interval) incurred in cardiogenic shock, followed by pulmonary oedema, 12,912 (11,006–15,148) €, and congestive HF, 9475 (8550–10,500) €.AHF leads to significant need for hospital care and high costs which differ significantly between clinical classes of AHF.