Endothelial nitric oxide synthase (NOS3) gene has been shown to modulate the degree of cerebral ischemia following stroke in animal models and is thus a candidate genetic risk factor for stroke. We compared 265 ischemic stroke cases with 293 controls and found no difference in distribution of the common structural variant Glu/Asp in codon 298 of exon 7 in the NOS3 gene. Our data do not support the hypothesis that NOS3 is a genetic risk factor for stroke.