MicroRNAs (miRNAs) are small non-coding RNAs of ~22 nucleotides in length that play important roles in controlling a huge range of eukaryotic cell functions. Many studies have shown that abnormal expression levels of miRNAs are associated with many diseases and detrimental health effects caused by exposure to environmental pollutants and particulate matter. As a number of reports suggest that profiles of miRNAs in body fluids reflect physiological and pathological status, extracellular miRNAs, especially in plasma and serum, are being focused on as candidate disease biomarkers. Although these phenomena suggest that expression levels of plasma miRNAs can also be used as biomarkers for the detection of adverse health effects caused by exposure to environmental pollutants, there are still few studies on this subject. In the present study, we used diesel exhaust (DE) and filtered-DE (F-DE), which is DE with the particulate matter removed, as a model for environmental pollutant exposure and comprehensively analyzed alteration of the expression levels of plasma miRNAs in mice using a LNA miRNA microarray. MiRNA microarray analyses showed altered expression level of 5 plasma miRNAs (miR-1983, miR-720, miR-1957, miR-335-3p, and miR-1897-5p) in the DE-exposed group and F-DE-exposed group. The results show both the possibility that exposure to various environmental chemicals including DE alters plasma miRNAs and the potential for plasma miRNAs to be used as biomarkers of exposure to these chemicals.