The causes of aortic regurgitation (AR) include rheumatic heart disease, infective endocarditis, and various congenital and degenerative defects. We report an unusual case of AR in a 72-year-old man due to an aortic root pouch. The diagnosis AR was made by cardiac echocardiography, and the cause was revealed by cardiac catheterization and 64-slice cardiac computed tomography. During aortic valve replacement, a saccular pouch between the noncoronary cusp and the right coronary cusp of the aortic valve was noted.