Backgrounds: It is well known that iatrogenic coronary ostial stenosis could be occurred after aortic valve replacement, but its mechanism has not been completely understood. Recently, aortic valvuloplasty using specially designed aortic ring was introduced as a new surgical technique for the aortic valve disease (CARVAR surgery), but it���s short and long term result have not been definitely confirmed. We present recently experienced consecutive 4 cases of iatrogenic coronary ostial stenosis after aortic valvuloplasty in patients who had aortic stenosis. Case reports: In the present 4 cases of aortic stenosis, pre-operative coronary angiography confirmed normal coronary arteries. They underwent aortic valvuloplasty with aortic leaflet extension with bovine pericardium and insertion of specially designed inner and outer ring at the level of sinotubular junction of ascending aorta. Within 5 months after surgery, patients complained resting chest pain and dyspnea with change of electrocardiography. Repeat coronary angiography demonstrated right coronary artery(RCA) ostial stenosis in 1 patient and left main(LM) ostial stenosis in the other 3 patients. Intravascular ultra sonography demonstrated that very severe ostial stenosis, and extensive echogenic tissue was observed in surrounding extravascular area of ostium. Three patients with LM ostial disease were successfully underwent coronary bypass graft surgery, and percutaneous coronary intervention with stenting was performed in 1 case of RCA ostial stenosis. Conclusion: This is a first description of the iatrogenic complication of CARVAR surgery. Because the ostial stenosis showed very poor prognosis and its developing mechanism has not been fully confirmed, more clinical study is required to confirm the safety and efficacy issue before the conventional use of CARVAR surgery.