We present a rare case of lipomatous hamartoma of the aortic valve. A 17-year-old woman was admitted with cardiac murmur. Echocardiography demonstrated severe aortic regurgitation and a highly echoic mass on the right cusp of the aortic valve. Surgery was performed with a differential diagnosis of chronic infective endocarditis or aortic valve tumor. At operation, a yellowish bead-shaped tumor was detected on the right cusp of the aortic valve, and aortic valve replacement was performed. Histopathological examination confirmed a lipomatous hamartoma. To the best of our knowledge, this is the first reported case of a lipomatous hamartoma located on the aortic valve.