The aim of this study was to investigate the net effect of raw carbon nanotube (CNTs) on the final properties of polyurethane (PU)/CNT composites considering their biomedical applications. So, neat PU and PU/CNT composites containing different amounts of CNTs (0.05%, 0.1%, 0.5%, and 1%) were prepared by electrospinning. Electrospinning parameters optimized to have a bead-free structure with no significant difference between their mean fiber diameter and porosity percentage. The results showed adding CNTs caused an increase in crystallinity percentage, water absorption ratio, young modulus, toughness, conductivity, degradation time in an accelerated medium, clotting time, and human umbilical vein endothelial cells adhesion. But a direct relationship between CNT percentage and the calcium adsorption was not detected. Moreover, no significant cytotoxicity was observed for 7-day extracts of all samples. These nanocomposites have a vast range of properties which make them a good candidate as neural, cardiovascular, osseous biomaterials or tendon, and ligament substitute.