A 30-year-old man presented with severe aortic regurgitation due to an ascending aortic aneurysm and mitral valve insufficiency in conjunction with active endocarditis. He underwent combined aortic root replacement by a composite graft and mechanical mitral valve replacement. After excision of the aortic valve cusps the mitral valve was approached through the extremely dilated aortic annulus. This technique is seldom used. Mitral valve replacement through the aortic root can be advantageous in selected patients to minimize trauma and reduce myocardial ischemic time.