Atherosclerosis is an inflammatory disease characterized by extensive lipid deposition and atherosclerotic plaque formation in the intima. Interleukin (IL)-37 is anti-inflammatory cytokine in the IL-1 ligand family. Given that IL-37 plays an important function in the development and progression of inflammatory and autoimmune diseases, it may be associated with the development of atherosclerosis. IL-37, which is normally expressed at low levels in peripheral blood mononuclear cells (PBMC), mainly monocytes, and dendritic cells (DC), is rapidly up-regulated in the inflammatory context, and therefore IL-37 conversely inhibits the production of inflammatory cytokines in PBMC and DC. In addition, IL-37 effectively suppresses the activation of macrophage and DC. It is not controversial that the activation of macrophage and DC and the over-expression of inflammatory cytokines are critical component elements in inflammatory process of atherosclerosis. Therefore, IL-37 may play a protective role in atherosclerosis through inhibition of inflammatory cytokines production and suppression of macrophage and DC activation.