Objectives Adropin is a newly identified secreted protein implicated in the regulation of insulin sensitivity and vascular endothelial function. Recent studies have shown that lower serum adropin level is related to acute myocardial infarction and coronary atherosclerosis. The primary objective of this study was to ascertain the association of serum adropin level with stable coronary artery disease (SCAD). Methods We prospectively recruited a cohort of patients with SCAD and similar sample size subjects without coronary artery disease as controls. Their serum adropin levels were measured, and the severity of coronary atherosclerosis in SCAD patients was quantified with the syntax score. Results A total of 116 patients with SCAD and 116 control subjects without coronary artery disease were recruited. Patients with SCAD had lower serum adropin levels when compared with the controls (59.2 +/- 19.3 versus 70.0 +/- 18.2 pg/mL, P<0.001). The multiple logistic regression revealed that low serum adropin level was a significant predictor of SCAD (AOR 0.976, 95% CI 0.960-0.992; p=0.003). Through the gamma regression model, it was further revealed that serum adropin level is significantly associated with syntax score (coefficient: -0.134, 95% CI: -0.212- -0.056; p=0.001). Conclusions Low serum adropin level is a significant predictor of SCAD. It is also associated with syntax score, thus indicating the close relationship between adropin and coronary atherosclerosis.