Tachycardia has negative impacts on hemodynamic status of patients with acute left ventricular failure and atrial fibrillation. In this patients, intravenous verapamil and beta-blocking drugs were not appropriate for the negative effects on left ventricular systolic function. In this study, we evaluated the effects of intravenous amiodarone on heart rate in patients with acute heart failure and atrial fibrillation and tachycardia. 30 patients with acute heart failure and atrial fibrillation and tachycardia were underwent intravenous amiodarone treatment. All patients were treated with also intravenous dobutamine and frusemide. All patients were in NYHA class 4. 3 mg/kg amiodarone were given first 30 minute and after I mg/min were infused. After the beginning of infusion, heart rate(beat/minute) and systolic and diastolic blood pressures (mm Hg) were determined at 0, 30, 60, 90, 120, 240, 360, 720. minute. We observed that, heart rate were progressively decreased without hypotension with intravenous amiodarone treatment. Conclusion: In this study we demonstrated that intravenous amiodarone has effectively lowered heart rate without hypotension in patients with acute heart failure and atrial fibrillation with tachycardia.