We report a 48-year-old man with inflammatory aortic aneurysm in the ascending aorta complicating severe heart failure due to massive aortic regurgitation. Continuous intravenous milrinone infusion was highly effective in reducing pulmonary arterial pressure and improving subjective symptoms during preoperative anti-inflammatory corticosteroid therapy over 7 weeks without any adverse effects or tolerance. Bentall's operation with a valved conduit was successfully performed after complete stabilization of inflammatory markers, and then milrinone was tapered off uneventfully. We consider that continuous milrinone infusion may be suitable for patients with surgically correctable inflammatory cardiovascular diseases complicating severe heart failure in whom maintenance of optimal hemodynamics is necessary for several weeks during preoperative anti-inflammatory corticosteroid therapy.