Replacement of the aortic valve in a normal or large aortic root can be accomplished with ease and safety in most instances. The presence of a narrowed aortic annulus remains a problem in that the replaced smaller prosthetic valve has a significant resting pressure gradient across the orifice. This narrowing causes not only technical difficulties, but also increased mortality and post-op. complication. Therefore this problem deserves special attention. This report presents our experience with a case of a small aortic root caused by rheumatic heart disease [AI and MS]. This is the method of enlargement of the aortic annulus with a woven Dacron patch and replacement of a larger prosthetic aortic valve combined with mitral valve replacement.[KTCS 1979;1:56-60]