Due to the ability to introduce or mutate genes, the mouse has become the most common experimental animal model for atherosclerosis research. Wildtype mice on a chow diet do not get atherosclerosis. Three ways to induce atherosclerosis in mice are discussed: diet-induced, apoE deficiency-induced, and LDL receptor-deficiency induced. The atherosclerotic lesions in apoE-deficient mice have been well characterized, and they resemble human lesions in their sites of predilection and progression to the fibroproliferative stage. These mouse models of atherosclerosis are being used to identify genes which modify atherosclerosis susceptibility and in the development of antiatherogenic therapies.