We performed aortic valve replacement in 2 patients with aortic regurgitation (AR) in whom a "dovecoo" murmur was heard. Here we discuss the valve shape and the origin of the heart murmur. In the 1st patient, echocardiography revealed prolapse of the right coronary valve cusp toward the left ventricular outflow tract during the diastolic phase and fibrillation of the valve leaflet due to the AR jet. In the 2nd patient, surgical findings revealed thickening of the middle part of the leaflet of the right coronary cusp, which caused prolapse of the right coronary valve cusp toward the left ventricle. We hereby report 2 rare cases of "dove-coo" murmur in which the cause of the murmur was morphologically confirmed by echocardiography in one case and by surgical findings in the other case.