A 51-year-old woman, who had undergone aortic valve replacement (SJM 19 mm) and open mitral commissurotomy for aortic valve stenosis with regurgitation, and mitral stenosis, was admitted for redo surgery. We found discrete subaortic ring just below the prosthetic valve. The fibrous ring was resected and the aortic valve was replaced (SJM 21 mm) after augmentation of the aortic annulus by Nicks procedure. Mitral and tricuspid valves were replaced. Discrete subaortic stenosis after aortic valve replacement are mostly in cases with small prosthetic valve. The turbulence caused by the small valve may produce discrete subaortic ring.