This review addresses a rapidly growing area of vascular biology, i.e. genomic variations in vascular genes that underlie different human phenotypes. Two of the most important molecular in vascular biology, endothelial nitric oxide synthase (eNOS) and vascular endothelial cell growth factor (VEGF)are discussed. Variations in the eNOS gene have been correlated with a number of human diseases including hypertension, coronary vasospasm, smoking dependent risk of coronary disease, myocardial infarction and placental disruption. Similarly, variations in the VEGF gene have been associated with increased risk of various cancers, DiGeorge syndrome, psoriasis, diabetic renal disease and amyotropic lateral sclerosis. Understanding the molecular basis of these genetic variations and how they contribute to the pathophysiology provides new and important insights into human disease.