The risk of hypertension was increased among tobacco users (either smoking/chewing or both) carrying eNOS intron 4 aa genotype (OR 14.00: 95% CI 1.20−163.37) in comparison with the subjects who had the habit of tobacco use (either smoking/chewing or both) belonging to eNOS intron 4 ab genotype (OR 8.06: 95% CI 4.41−14.73) and eNOS intron 4 bb genotype (OR 4.09: 95% CI 2.74−6.12). The gene discussed is NOS3; the disease is Hypertension.