Myung, Keun Song*, M.D., Sam Hyun Kim*, M.D. Chong Whan Kim*, MD.. Kyung Phill Suh*, M.D. and Yung-Kyoon Lee*, M.D. Congenital aortic stenosis, a relatively uncommon congenital heart disease, may cause heart failure and may be fatal. In recent years, increased clinical awareness and improved diagnostic and operative technique has made accurate diagnosis and successful treatment possible. Recently we experienced 2 cases of congenital aortic stenosis, and which was corrected surgically. The first case was 9 years old boy, and second case was 16 years male. Preoperative diagnosis was entertained by angiography and cardiac catheterization in both cases. In each case, aortic valve opening was widened by incision along the fused commissure between the combined left and right coronary cusp on one side, and the noncoronary cusp on the other side. Post-op. pressure gradient between the aorta and left ventricle markedly reduced, in the first case, 50mmHg, and in the 2nd case, 55mmHg.Both patients discharged with good results 2 weeks after open heart surgery.[KTCS 1978;2:194-198]