Vascular endothelial growth factor (VEGF) is a potent angiogenic cytokine implicated in tumour vasculogenesis. A significant increase in vascularity occurs during the transition from normal oral mucosa (NOM), through dysplasia, to squamous cell carcinoma (SCC). This study investigated the presence of VEGF in NOM, oral dysplasia and SCC. The correlation between VEGF expression and the grade of dysplasia or differentiation of SCC was also examined. Specimens consisting of NOM, oral dysplastic lesions and oral SCC were stained using standard immunohistochemistry methods to determine VEGF expression. Statistical analysis indicated an up-regulation of VEGF during the transition from NOM, through dysplasia to SCC. There was also a significant difference in expression according to differentiation of SCC, but not grade of dysplasia. As VEGF is a potent mediator of vascular development, these results suggest that VEGF may play an important role in the maintenance of a blood supply for developing pre-cancerous and invasive oral lesions.