BACKGROUND: Endothelial dysfunction are associated with vasospastic angina, essential hypertension, and other cardiovascular risk factors. Asymmetric dimethylarginine(ADMA), an endogenous inhibitor of NO synthase, is known to induce endothelial dysfunction. But, a few data are available about the relationship between ADMA and cardiovascular disease in Korea. We investigated the association of ADMA concentration in serum with vasospastic angina, essential hypertension, and other cardiovascular risk factors. METHODS: Patients with chest pain who underwent both diagnostic coronary angiography with spasm test were enrolled for the study. ADMA serum levels were measured by enzyme-linked immunosorbent assay(ELISA). RESULTS: Among total 116 patients, 34%(39/116) showed positive at spasm test and 60%(69/116) had hypertension. There were significant differences in serum ADMA according to coronary spasm(p=0.004) and metabolic syndrome(p=0.012), not in hypertension(p=0.445). ADMA had a positive correlation with age(r=0.289, p=0.001), CRP(r=0.224, p=0.015), and insulin(r=0.164, p=0.047). CONCLUSION: In this small study we found serum ADMA was associated with vasospastic angina and metabolic syndrome, but not with hypertension. And we found positive relationship of ADMA with age, C-reactive protein(CRP), and insulin, respectively. So, this hypothesis should be tested in a larger study group.