Cell adhesion molecules (CAMs) have been implicated in various biologic processes, including morphogenesis, immune response, and thrombosis. There are four major groups: integrins, cadherins, immunoglobulin superfamily members, and selectins. Certain CAMs are differentially expressed in the developing, normal, and cancerous kidney. Other CAMs are altered in glomerulonephritis and transplant rejection. Preliminary studies suggest that blocking CAMs can attenuate tissue damage in human transplant rejection and animal models of glomerulonephritis. The study of CAMs in relation to the kidney is providing further insight into the normal and diseased kidney, and may lead to feasible new treatments for patients with renal diseases.