Although the aetiology of polyps is still, for the most part, unknown, the disease is known to involve tissue oedema. Vascular permeability/vascular endothelial growth factor (VPF/VEGF) is a major inducer of angiogenesis and capillary permeability. This study investigated VPF/VEGF expression in biopsies of nasal polyps from 39 patients and in healthy nasal mucosa from 10 patients by immunohistochemical staining. Staining for VPF/VEGF in the mucosal surface and in the glandular epithelium of nasal polyps was weaker than in normal controls. In two patients, strong staining for VPF/VEGF was found in a granular pattern in mast cells, while the mast cells in other polyposis patients appeared to be largely degranulated. VPF/VEGF was not seen in the mast cells of control patients. Although expression of VPF/VEGF was not increased in the epithelium of the nasal polyps, VPF/VEGF secreted from mast cells may take part in nasal polyp formation.