OBJECTIVE Oral Lichen Planus (OLP) is a chronic inflammatory disease with an autoimmune inflammatory pathogenesis. The aim of the research is to compare the vascular endothelial growth factor (VEGF) and adhesion of molecules in the biopsy samples of patients affected by OLP, in order to research the presence of the angiogenetic phenomenon and to understand its pathogenetic mechanism. METHODS Thirty OLP patients and thirty healthy subjects were enrolled in a study. The immunohistochemical analysis of the VEGF and vascular-endothelial adhesion molecules was carried out by means of primary antibodies and anti-CD34, anti-VEGF, anti-CD106 antigen (VCAM-1) and anti-CD54 antigen (ICAM-1). The statistical significance of the differences was checked with the Mann-Whitney test (MW test). The level of significance was set to P<0.001. Data analysis was carried out with StatView 5.0.1 (SAS Institute Inc., Cary, NC). RESULTS The results reveal the presence of a significant angiogenesis in OLP patients for the VEGF, CD34, CD106 and CD54 (P < 0.001).. The number of vessels in the biopsies of the patients with OLP (mean +/-SD: 21.27+/-4.85), compared with the healthy subjects (mean +/-SD: 4.74+/-0.97) was significantly more (Mann-Whitney test, P < 0.001). The positive expression rate of VEGF, CD34, VCAM-1 and ICAM-1 in oral lichen samples was 64.2%, 54.3%, 32.5% and 29.7%, respectively. Isolated endothelial cells and newly-formed micro-vessels and endothelial cells with high-immune-positivity to the antibodies anti-ICAM-1 and anti-VCAM-1 were observed. CONCLUSIONS The results of our immunohistochemical research show that a significant neoangiogenesis occurs in oral lichen planus.