The present invention relates to the use of tolerogenic dendritic cells in treatment and/or prevention of atherosclerosis. The cells have preferably been pretreated with at least one cytokine selected from the TGF-beta superfamily, such as TGF-beta-2, and/or with interleukin-10. Preferably, the cells have also been loaded with an autoantigen of atherosclerosis, such as the LDL protein, ApoB100 or a peptide thereof.