Statins may provide benefits, both by decreasing cholesterol and by the use of lipid-independent mechanisms. Extensive research carried out recently suggests that the clinical benefits of these drugs could be related to an improvement in endothelial dysfunction, a reduction in blood thrombogenicity, anti-inflammatory properties, and immunomodulatory actions. It is thought that they will become valuable tools for controlling inflammatory and immune responses. The chapter discusses the positive role of statins in the treatment of autoimmune reactions. The identification of several mechanisms through which statins decrease the recruitment of macrophages and T cells into the arterial wall and inhibit T-cell activation and proliferation in vitro have confirmed speculations that the immunomodulatory effects of statins may also be beneficial in the prevention of cardiovascular events. Many of these effects are related to the inhibition of isoprenoid synthesis, which serves as a lipid attachment for a variety of proteins implicated in intracellular signaling.