A great number of basic and clinical studies show that atherosclerosis is a chronic inflammatory disease and that inflammatory responses exist in all stages of development of atherosclerosis. Despite a lot of progress was made in recent years, the detailed mechanisms modulating the inflammation in atherosclerosis have not been fully elucidated. MicroRNAs (miRNAs) are a category of small non-coding RNAs with the length of about 21 to 25 nucleotides that regulate gene expression post-transcriptionally through degradation and translational repression of target messenger RNAs (mRNAs). Substantial evidence demonstrates that miRNAs play vital roles in cardiocerebrovascular diseases. miR-155-mediated regulation is extensively involved in endothelial cells, macrophages, dendritic cells, vascular smooth muscle cells, leukocytes and platelets. miR-155 can modulate the expression of inflammation-related genes which affect the development of atherogenesis. This paper reviewed the regulatory roles of miR-155 in various cell types involved in atherosclerosis.