Vascular diseases are increasing health problems affecting >25 million individuals in westernized societies. Such patients could benefit fromtransplantation of tissue-engineered vascular grafts using autologous cells. One challenge that has limited this development is the need for cell isolation, and risks associated with ex vivo expanded stem cells. Herewe demonstrate a novel approach to generate transplantable vascular grafts using decellularized allogeneic vascular scaffolds, repopulatedwith peripheralwhole blood (PWB) in vitro in a bioreactor. Circulating, VEGFR-2+/CD45+ and a smaller fraction of VEGFR-2+/CD14+ cells contributed to repopulation of the graft. SEMmicrographs showed flat cells on the luminal surface of the grafts consistentwith endothelial cells. For clinical validation, two autologous PWBtissue-engineered vein conduits were prepared and successfully used for bypass procedures in two pediatric patients. These results provide a proof of principle for the generation of transplantable vascular grafts using a simple autologous blood sample, making it clinically feasible globally.