Endothelin (ET)‐1 causes proliferation of vascular smooth muscle cells (VSMC). Although it has been reported that stimulation of ET_B receptors as well as ET_A receptors promote proliferation of VSMC, the precise distribution of each receptor subtype in atherosclerotic vessels is unknown. Previous studies demonstrated that apolipoprotein E (apoE)‐deficient mice have hypercholesterolaemia and develop severe atherosclerosis. To investigate the pathophysiological roles of vascular ET system in atherosclerosis, we examined preproET‐1 messenger ribonucleic acid expression in the aorta of apoE‐deficient mice, and performed immunohistochemical staining for ET‐1 and each ET receptor subtype (ET_A and ET_B receptors) in the atherosclerotic lesions of these mice. The level of preproET‐1 mRNA in the aorta was significantly higher in the apoE‐deficient mice than in the control mice. Strong ET‐1 staining was observed in the macrophage‐foam cells, intimal and medial VSMC in the atherosclerotic lesions of the apoE‐deficient mice. In addition, in the atherosclerotic lesions, strong ET_B receptor staining was observed in the macrophage‐foam cells, intimal and medial VSMC, which distribution corresponded closely to that of ET‐1. ETA receptor staining was observed in the medial VSMC of both groups, but not in the macrophage‐foam cells of the apoE‐deficient mice. ET_A receptor staining in the medial VSMC was stronger in the apoE‐deficient mice than in the control mice. These results suggest that the vascular ET system, including ET‐1 and ET receptors, is activated in the atherosclerotic lesions of apoE‐deficient mice. Since the distribution of strong ET_B receptor staining corresponded closely to that of ET‐1, it is suggested that the ET system, mediated by ET_B receptors, has an important role in the pathophysiology of the atherosclerotic lesions of apoE‐deficient mice.