Introduction: Endothelial dysfunction with a systemic alteration in nitric oxide production may be a cause of variant angina pectoris (VAP). Plasma adiponectin is decreased in patients with coronary artery diseases especially in patients with acute coronary syndrome (ACS). However, the correlation between plasma adiponectin and VAP, to our knowledge, has never been studied. We investigated the implications of plasma adiponectin in VAP. Methods: Patients (n=395, 180 women and 215 men) with suspected coronary artery disease were divided into four groups: ACS (n=117), VAP (n=94), stable angina pectoris (SAP) (n=108), and normal coronary (n=76). Results: Plasma adiponectin concentration in VAP was significantly lower than that of normal coronary group (6.6 짹 5.4 vs. 9.0 짹 6.2 ug/mL, p<0.001). Patients in VAP were younger compared with those of SAP and ACS (56.6 짹 10.5 vs. 61.3 짹 10.3, p=0.008 and 56.6 짹 10.5 vs. 61.4 짹 10.3, p=0.005, respectively) and showed significantly higher rates of current smoking (p=0.042 by ANOVA). Multivariate analysis showed that plasma adiponectin (odd ratio [OR] 0.724, 95% confidence interval [CI] 0.660 to 793, p=0.005), smoking (OR 2.033, 95% CI 1.110 to 3.725, p=0.022), and age (OR 0.967, 95% CI 0.940 to 0.995, p=0.019) correlated independently with the development of VAP. Conclusion: Our results suggest that a decrease in plasma adiponectin concentration might be associated with the development of VAP. Plasma adiponectin concentration may be used as a predictor of VAP in addition to other risk factors such as smoking and age.