The retrospective cost analysis estimates direct in-patient costs and length of stay (LOS) in hospital for acute heart failure (AHF). Patients were hospitalized with acute decompensation (ADHF) or de novo AHF in the Faculty Hospital Brno in 2005 and 2006. Burden incurred is divided to standard cardiology unit (SCU) and intensive care unit (ICU). In-patient care costs include flat rate of admission, stay and medicinal procedures. The pharmaceuticals are included in daily in-patient rate; angiography, revascularizations and antiarrhythmic interventions are calculated separately. In total, 734 patients (57% male, mean age 71.7 years) with AHF were analyzed. De novo AHF (58.6%) was more common than ADHF; according to the clinical classification AHF with mild signs and symptoms prevailed (46%). The overall direct hospital cost of all patients was €2.4 million, mean LOS was 8.3 days and mean in-patient cost was €3295 (including all interventions). Almost a half passed through both SCU and ICU with LOS 10.8 days; mean LOS in the SCU was 8.3 days with one-day cost of €55; mean LOS in the ICU was 3.4 days with one-day cost of €618. Total cost of cardiac catheterizations and revascularizations (50% patients) was almost a million; cost of antiarrhythmic interventions was €529216 (implantation of pacemaker, implantable cardioverter-defibrillator or cardiac resynchronization therapy with biventricular device; 6.9% patients). Mortality during hospitalization was 14.6%. AHF is associated with poor prognosis and high costs during hospital admission; the predominant contributors of high costs are revascularization procedures (39%), stay in the ICU (31%) and antiarrhythmic interventions (22%).