The aim of the present study was to evaluate the association of vascular endothelial growth factor (VEGF) and its receptor, KDR/Flk-1, with tumor grade, microvessel density (MVD) and clinical outcome in patients with soft tissue sarcomas (STSs). Tissue specimens of 28 patients with STSs were analyzed immunohistochemically using specific monoclonal antibodies. Tissue samples were obtained prior to any treatment. Half of the STSs exhibited strong expression of VEGF that was associated statistically significantly with high tumor grade. Strong expression of KDR/Flk-1 was detected in only 2 sarcomas. No association was demonstrated between VEGF and KDR/Flk-1 expression. MVD was significantly associated with tumor grade and was higher in sarcomas with strong VEGF expression. Limited data on clinical outcome precluded solid analyses for an association with disease progression. This study provides further evidence on the role of VEGF and MVD in tumor aggressiveness in STSs.