Innate and adaptive immunity has been shown to be critically involved in the pathogenesis of atherosclerosis. In particular, immune suppression mediated by regulatory T cells (Tregs) or tolerogenic dendritic cells (DCs) serves as a vital mechanism for regulating pathogenic chronic inflammation in atherogensis, suggesting that promotion of endogenous regulatory immune responses could be a possible therapeutic approach to suppress atherosclerotic disease. In this review, we discuss the possible role of Tregs and tolerogenic DCs in the prevention of atherosclerosis and the promising strategies to prevent or cure atherosclerotic disease by modulating regulatory immune responses mediated by these suppressor cells.