Extracellular matrix (ECM) within the vascular network provides both a structural and regulatory role. The ECM is a dynamic composite of multiple proteins that form structures connecting cells within the network. Blood vessels are distended by blood pressure and, therefore, require ECM components with elasticity yet with enough tensile strength to resist rupture. The ECM is involved in conducting mechanical signals to cells. Most importantly, ECM regulates cellular function through chemical signaling by controlling activation and bioavail-ability of the growth factors. Cells respond to ECM by remodeling their microenvironment which becomes dys-regulated in vascular diseases such hypertension, restenosis and atherosclerosis. This review examines the cellu-lar and ECM components of vessels, with specific emphasis on the regulation of collagen type I and implications in vascular disease.