ABsTRACfIn this manuscript the pathology ofhumanarterialdisease, including diseases ofthe aorta,coronary arteries, and peripheral arteries, is reviewed. Common atherosclerotic-related lesions and varied forms of aortitis, arteritis, and dissecting aneurysms are described in terms of their gross and microscopic characteristics. In addition,rareroccurrences, suchas congenital hypoplasia ofthe arteries, are mentioned. Finally, morphologic changes in blood vessels that have been affected by drugs or toxins are summarized.