We sought to assess the prevalence of atherosclerotic lesions in the human brachial artery.Many investigators have recently studied endothelial and vascular function in the brachial circulation in humans to further their understanding of coronary artery disease and early atherogenesis. However, the prevalence of brachial atherosclerosis and its relation to coronary disease have never been documented.Arterial segments from the brachial, common carotid and left anterior descending coronary arteries were obtained during autopsy in 52 consecutively examined subjects (35 men, 17 women; 21 to 79 years old, mean [+/-SD] age 51 +/- 16) and studied by light microscopy using standard histologic techniques. Severity of the atherosclerotic lesions was categorized as fatty streaks (grade 1), fibrous plaques (grade 2) and advanced lesions (grade 3).Atherosclerotic lesions of any grade were found in the brachial artery in 39 (75%) subjects, common carotid artery in 51 (98%) and left anterior descending coronary artery in 52 (100%), and the prevalence and severity of disease increased with age in all three arteries. The grade of lesion severity in the brachial and coronary arteries was significantly correlated (r = 0.41, p = 0.003), as was severity in the brachial and carotid arteries (r = 0.53, p = 0.0001) and the carotid and coronary arteries (r = 0.69, p = 0.0001). The correlation between the brachial artery and the left anterior descending coronary artery was highly significant in subjects or = 50 years old (r = 0.37, p = NS).Atherosclerosis is common in the human brachial artery and is significantly correlated with both coronary and carotid disease. These results suggest that the brachial circulation may serve as a reasonable "surrogate" for studying atherosclerosis, particularly in younger adults.