The mathematical model of vasogenic brain oedema, which was presented at the previous meeting in 1987, was applied to the analysis of peritumoural brain oedema associated with meningiomas. Magnetic resonance images of 90 patients with intracranial meningiomas were reviewed to analyze the spatial extension of peritumoural brain oedema. It is assumed that the heterogeneous pattern of distribution of peritumoural oedema reflects the variability of the compact density of the fibers in the white matter. A two dimensional finite element model was constructed with 786 triangular elements from a horizontal section of the human brain. The development of oedema, the change of interstitial pressure, the deformation of the brain and the absorption of oedema fluid could be simulated by the finite element method. The result of computer simulation represented interactive behaviour of the brain tissue, extracellular fluid, and cerebrospinal fluid in the clinical situation. The finite element method (FEM) may provide a new experimental tool to analyze the pathophysiology of vasogenic brain oedema.