Subject of investigation was the demonstration of the different expression of ICAM-1, and VCAM in 13 complete cross sections of the Aorta abdominalis and the Arteria iliaca immediately available post operationem during the process of arteriosclerosis. With increasing severity of the arteriosclerosis, ELAM showed a decreasing expression of the endothelium of the main vessel and a moderate one of the cells in the adventitia. On the endothelium of the main vessel and the vasa vasorum, we detected ELAM-1, showing a decreasing tendency when the arteriosclerosis was aggravating. In case of severe arteriosclerosis, a focal expression was also found on cells in the intima and media. In the adventitia, the expression was relatively constant during the process of arteriosclerosis. The more serious the disease, the more provable was VCAM on endothelial cells. In cases of severe arteriosclerosis, we also detected a focal staining in deeper layers of the wall. This study supports the concept of the active role of endothelial cells in the recruitment of leucocytes during the early steps of the arteriosclerotic process. In this process, with the disease aggravating, the endothelium seems to be less significant than the smooth muscle cells, which obviously play an important role in the course of arteriosclerosis.