There is an important clinical need for suitable vascular grafts, especially for small diameter vessel replacements in adult patients and for pediatric reconstructions. The objective of this thesis was to develop a synthetic biodegradable vascular graft to guide the regeneration of a natural artery. The developed graft was made of micro and nano fibers of polycaprolactone, forming a porous, but mechanically strong structure. The long term in vivo performance of the graft was evaluated in an aortic replacement in the rat model for 18 months and showed very promising results and no occlusions were observed. Two strategies were then investigated to improve the tissue regeneration in the wall of the degrading graft: modifying the micro-architecture of the scaffold and modifying the hydrophilicity of the synthetic polymer. With both strategies, significant improvements to the arterial regeneration were achieved. This research contributes to the advancement of biodegradable vascular grafts towards clinical use.