Autopsy specimens of human coronary arteries were collected from 65 men and women ranging in age from 40-76 years of age. We made 209 coronary artery sections, which were graded in terms of severity of atherosclerosis by means of the Stary classification. Sections were stained using an antibody directed against the angiotensin II type 1 (AT1) receptor. We found that in non-atherosclerotic sections, staining was confined to vascular smooth muscle cells in the media. However, with the advent of atherosclerosis, AT1 receptor expression was also present in atherosclerotic plaque and involved other cell types including inflammatory cells and myofibroblasts. We identified a remarkable correlation between AT1 receptor staining and the severity of coronary atherosclerosis as well as intima-media thickness. These human data correspond well to animal models of atherosclerosis indicating an upregulation of AT1 receptor expression in atherosclerotic tissue.