The carbohydrate moieties of the glycocalyx of the retinal capillary endothelium were demonstrated using lectin-affinity cytochemistry. The endothelial surface was rich in sialic acid, N-acetylglucosamine, galactose and mannose. Low levels of N-acetylgalactosamine were present. There was no preferential distribution of lectin-receptor monosaccharides on the cell surface. The binding of all lectins was inhibited by the appropriate hapten sugars and by perfusion of trypsin or pronase prior to labeling. No differences were observed between vessels in the inner and outer retina.