We reported a 29-year-old man with active endocarditis complicating aortic and mitral valve regurgitation. The echocardiogram showed a mycotic aneurysm at aortic valvular annulus and a aneurysm of mitral valve. Heart failure was progressive and caused anuria. Prior to emergent double valve replacement, 2,500 ml of water was removed. Then hemodynamics became stationary. Urination was good during and after operation. In this case, complicating acute renal failure, dehydration with extracorporeal ultrafiltration method was very effective for improvement of hemodynamics.