OBJECTIVE: To study the relationship between the expression of vascular endothelial growth factor (VEGF) and peritumoural brain edema (PTBE) in meningiomas. METHODS: The expression of VEGF was investigated in 40 specimens of intracranial supratentorial meningioma resected during operation, using immunohistochemical techniques. The expression of factor VIII-related antigen (VIII-R Ag) was examined by immunohistochemistry so as to calculate the microvascular density (MVD). The formulae V = 4/3pi x abc and EI = V(edema) + V(tumor)/V(tumor) were used to determine the edema index (EI). The results of staining were compared with the data by MRI and neuroradiology in double blind fashion. RESULTS: Compared to VEGF-negative meningiomas, tumours with striking VEGF staining revealed a significantly higher mean EI (4.6 vs. 1.5, P = 0.003), higher edema incidence (88.2% vs. 41.7%, P = 0.023 68), and higher MVD (53.0 vs. 26.5, P = 0.018). Equally, meningiomas with pial supply revealed a significantly higher mean EI than meningiomas with only dural supply (4.4 vs. 1.8, P = 0.044). Meningiomas severely adhered to brain revealed a higher edema incidence than those with milder adhesion (88.9% vs. 45.5%, P = 0.004 17). The tumour volume did not correlate with EI (P > 0.05). CONCLUSION: The VEGF expression and tumour angiogenesis are correlated with peritumoural brain edema. The rate of brain edema is higher in the tumors with pial supply and severe adhesion with brain. There is no a significant correlation between the tumour volume and edema degree.