Nitric oxide (NO), which modulates endothelial function, is thought to be pivotal in the pathophysiology of migraines. The connection between migraine and cardiovascular diseases has also drawn attention to the endothelial dysfunctions and NO pathway abnormalities seen in patients with migraine. Our goal was to assess the levels of NO and the endogenous NO synthase inhibitor, asymmetric dimethylarginine (ADMA), in people with migraine during the interictal period. A total of 49 patients with migraine and 22 control subjects were enrolled in the study. Their plasma NO metabolites (nitrite [NO2-] and nitrate [NO3-]) and ADMA levels were measured using the enzyme-linked immunosorbent assay method, and were then compared with their cardiovascular risk factors, anthropometric measurements, and headache frequency and severity. The plasma ADMA, NO2- and NO3- levels of the patients with migraine during the interictal period did not differ from the control group, and no relationship was found between cardiovascular risk factors and migraine attack severity and frequency. We conclude that, in patients with migraine, there is no dysfunction of baseline NO and ADMA metabolism during the interictal period.