Interactions of endothelial cells with T cells occur during the process of lymphocyte migration and during leukocyte extravasation in the course of an inflammatory response. Adhesion molecules are crucially involved in these interactions. It has been assumed that, in this way, endothelial cells play an important role in the recruitment of immune cells to sites of inflammation. In vitro experiments indicate that, in addition to this function in leukocyte recirculation, endothelial cells might also be involved as accessory cells in the stimulation of T cells. In this overview, the possible role of adhesion molecules in this process will be discussed.