Vascular gene transfer is the introduction of foreign DNA into host cells within the vessel wall. Expression of recombinant genes within vascular cells has been demonstrated in normal, injured and atherosclerotic arteries. Transfer of genes with biological activity has provided insights into the role of specific genes in normal and pathological states. The development of gene transfer as a form of vascular therapy will require safe and effective vectors and intravascular delivery systems. Viral and non-viral vectors and several delivery catheters are being evaluated to determine their clinical applicability. The current applications of vascular gene transfer to cardiovascular diseases are the prevention of restenosis following arterial injury and induction of angiogenesis in occlusive vascular disease.