Cells of both the innate and adaptive immune system participate in the development of atherosclerosis, a chronic inflammatory disorder of medium and large arteries. Natural killer T (NKT) cells express surface markers characteristic of natural killer cells and conventional T cells and bridge the innate and adaptive immune systems. The development and activation of NKT cells is dependent upon CD1d, a MHC-class I-type molecule that presents lipids, especially glycolipids to the T cell receptors on NKT cells. There are two classes of NKT cells; invariant NKT cells that express a semi-invariant T cell receptor and variant NKT cells. This review summarises studies in murine models in which the effect of the activation, overexpression or deletion of NKT cells or only invariant NKT cells on atherosclerosis has been examined.