A tissue-engineered small diameter blood vessel was developed by seeding endothelial cells onto a collagen matrix that was cross-linked and contracted by smooth muscle cells onto a polyester scaffold. Endothelial cells (EC) and smooth muscle cells (SMC) were isolated using enzyme dissociation of porcine aorta. Batches of these cells were accredited by immunohistochemical characterisation and functional assay prior to being used in any experiments. Once deemed suitable, they were cryopreserved for later use. Initial experiments determined the optimum SMC and collagen concentrations for producing a cellular rich collagen matrix. The use of a synthetic permanent polyester scaffold provided structural integrity for the developing blood vessel. Dedicated and robust bioreactor vessels and a pulsatile flow circuit were developed to be able to sustain the biologically active tissue and maintain physiological homeostasis. The retention of radiolabelled endothelial cells seeded onto the luminal surface of the grafts was assessed under conditions of high shear stress. The effect of surface modification using a variety of extracellular matrix proteins and low shear stress preconditioning of the SMC matrix was also assessed for its ability to enhance EC retention. Invivo evaluation of these tissue engineered grafts using a porcine model of infrarenal aortic implantation was finally carried out using standard Dacron grafts as controls.