Background: Nitric oxide (NO) synthesized by endothelial cells is known to be a potent vasodilator. It has been suggested that polymorphisms in endothelial nitric oxide synthase (eNOS) can affect the response of the vascular endothelium to increased oxidative stress. The objective of the present study was to determine the presence of G894T (rs1799983), intron-4 (27-bp TR) and -T786C (rs2070744) polymorphisms in the eNOS gene among the Colombian general population.Results: Genotype and allele frequencies showed significant differences in their distribution. White, black and mixed populations were in HW equilibrium for the variants in 27-bp TR- and rs1799983, but the black population was in HW disequilibrium for rs2070744 (p < 0.001). Allele "T" of rs1799983 polymorphisms was more common in the white population (26,5%) than the others, while allele "C" of rs2070744 polymorphisms had a similar frequency in all populations, and the allele 4a from 27-bp TR was more frequent in the black population (26,2%) than the others. Similar differences were found when genotypes were analyzed.Conclusion: The findings suggest that there is a substantial difference in the distribution of eNOS polymorphisms between different ethnic groups. These results could aid the understanding of inter-ethnic differences in NO bioavailability, cardiovascular risk, and response to drugs.