This study was undertaken to determine whether vascular dendritic cells (VDCs) display VCAM-1 in atherosclerotic lesions. Specimens of carotid artery and aorta were obtained at operation. All the plaques contained VCAM-1+ cells, but VCAM-1 immunoreactivity was irregularly distributed being mainly associated with the zones of neovascularisation in the base of the atherosclerotic plaques. Vascular dendritic cells were identified with DAKO-CD1 a. Alternative parallel sections were stained with either anti-CD1 a or anti-VCAM-1. By comparison of consecutive parallel sections the CD1a+ vascular dendritic cells were located separate from other intimal cells. In some areas networks formed by VCAM-1+ vascular dendritic cells were observed suggesting that cellular networks may mediate a local immune response in atherosclerotic lesions. We speculate that VCAM-1 is involved in the formation of cell-to-cell contacts of vascular dendritic cells in atherogenesis.