Leukocyte recruitment is integral to both the innate and adaptive immune response. Leukocytes extravasate to sites of inflammation, injury or infection and leukocyte recruitment is crucial to a variety of inflammatory and autoimmune diseases. The process of leukocyte extravasation comprises a complex multistep cascade of adhesive interactions between leukocytes and the endothelium in the vessel wall. These adhesive events are tightly orchestrated by the crosstalk between adhesion receptors on both leukocytes and endothelial cells, as well as by several chemokine receptors, and control how different leukocyte subpopulations are recruited into specific tissues. Targeting leukocyte recruitment is of great therapeutic importance in inflammatory pathologies; specific inhibitors of leukocyte recruitment have already been used successfully in autoimmune diseases. Thus, understanding of the mechanisms regulating the leukocyte adhesion cascade as well as the tissue- and vascular bed-specific leukocyte recruitment will allow for the development of further novel therapeutic approaches with potential application in inflammatory and autoimmune diseases. The present review will (a) focus on the molecular mechanisms of the leukocyte adhesion cascade governing the interactions between leukocytes and endothelial cells and (b) address the potential role of leukocyte-endothelial interactions in the retina, and in particular, the potential role of inflammation in diabetic retinopathy.