The aorta and coronary arteries of two tortoise species, Testudo graeca ibera and Emys orbicularis are investigated. The elastic aorta of the first species showed minimal focal intimal thickenings while the muscular aorta of the second presented marked diffuse hyperplasia narrowing the caliber of the vessel. The author discusses this striking finding of the aortic structural differences between the two species investigated as well as the significance of such lesions for atherosclerosis development.