Circulating microRNA (miR)-208a is specifically expressed in the heart muscle, which is involved in the regulation of myosin during cardiac development. Previous studies reported that cardiac-specific miR-208a level is significantly higher in plasma of coronary heart disease (CHD) patients. However, whether it correlates with severity of CHD, has never been elucidated before. The aim of this study was to explore the association between miR-208a and the presence and severity of CHD. Samples were collected from 290 CHD patients and 110 subjects with angiographic exclusion of CHD. Circulating miRNA-208a expression was detected using quantitative real-time PCR. The Gensini score was used to evaluate the severity of coronary stenotic lesions. Expression of miRNA-208a was identified on the basis of the quartiles of the Gensini score, and association between the miRNA-208a levels and CHD was analyzed. Diagnostic potential of miR-208a of CHD was performed by ROC analysis. CHD patients had higher miRNA-208a expression (1.61, 0.45-3.86 vs. 0.66, 0.11-1.42, p < .001), and the biomarker level significantly increased following an increasing the Gensini score (p < .001). Gensini score was significantly associated with miRNA-208a expression (r = 0.8525, p < .001). The optimal cut-off value of the relative level of miR-208a was with a specificity of 93.6% and a sensitivity of 75.5%. The AUC of miR-208a was 0.919 (95% CI, 0.893-0.945; p < .001). These preliminary results suggest that the expression of miR-208a may be associated with atherogenesis. The level of circulating miR-208a in predicting the severity of coronary atherosclerosis may have a relatively certain value.