Different forms of vascular endothelial growth factor (VEGF) and their cellular receptors (VEGFR) are associated with angiogenesis, as demonstrated by the lethality of VEGF-A, VEGFR-1 or VEGFR-2 knockout mice. Here we have used an in vitro angiogenesis model, consisting of human microvascular endothelial cells (hMVEC) cultured on three-dimensional (3D) fibrin matrices to investigate the roles of VEGFR-1 and VEGFR-2 in the process of VEGF-A and VEGF-C-induced tube formation. Soluble VEGFR-1 completely inhibited the tube formation induced by the combination of VEGF-A and TNFα (VEGF-A/TNFα). This inhibition was not observed when tube formation was induced by VEGF-C/TNFα or bFGF/TNFα. Blocking monoclonal antibodies specific for VEGFR-2, but not antibodies specifically blocking VEGFR-1, were able to inhibit the VEGF-A/TNFα-induced as well as the VEGF-C/TNFα-induced tube formation in vitro. PlGF-2, which interacts only with VEGFR-1, neither induced tube formation in combination with TNFα, nor inhibited or stimulated by itself the VEGF-A/TNFα-induced tube formation in vitro. These data indicate that VEGF-A or VEGF-C activation of the VEGFR-2, and not of VEGFR-1, is involved in the formation of capillary-like tubular structures of hMVEC in 3D fibrin matrices used as a model of repair-associated or pathological angiogenesis in vitro.