A case of a 29 year old man with congenital aortic stenosis who developed a subvalvular annular aneurysm of the left ventricle after being run by a car is presented. At surgery his aortic valve was replaced and the opening of the aneurysm was closed with a patch of Dacron. Due to the dense adhesions to the aorta and left atrium no attempts were made to excise the sac, that was not compromising the dynamics of any one of these structures.