Objectives. To determine the relationship between angiogenesis and various histopathologic features as well as clinical outcome in patients with localized renal cell carcinoma (RCC). Methods, Microvessel density was quantified by using immunocytochemical staining of endothelial cells for factor VIII-related antigen of 36 specimens taken from patients with pathologic Stage pT1 or pT2 RCC. All patients underwent radical nephrectomy and were followed for a mean time of 97.3 months. Results. No association was noted between microvessel count (MVC) and either cell type, architecture, or tumor size. Inverse correlation was noted between MVC and nuclear area (P = 0.006), nuclear elipticity (P = 0.016), nuclear roughness (P = 0.039), and histologic grade (P = 0.047). Patients having tumors with low MVC had significantly better survival rate compared with those with high MVC neoplasms (P = 0.0014, by Cox proportional hazards method). Conclusions, Despite lack of correlation with known predictors of survival, MVC provides independent prognostic information for patients with localized RCC. (C) 1998, Elsevier Science Inc. All rights reserved.