The present study investigates relationships between neovascularisation and PCNA cell proliferation markers in different pathological lesions of the oral cheek mucosa. All specimens were fixed in 10% formalin and routinely processed for histology. Six normal (N) samples were taken from resection margins of benign lesions. The pathological lesions consisted of chronic inflammation (n = 10), lichen planus (n = 7), fibrous hyperplasia (n = 11), dysplasia (n = 5), squamous cell carcinoma (n = 22) and epithelium adjacent to carcinoma (n = 6). Adjacent 5 microns sections were stained with monoclonal antibodies against vimentin (clone no. V9) for identification of stromal blood vessels and against proliferating nuclear antigen (PCNA/PC10) using ABC immunoperoxidase techniques. Point counting was used to obtain the primary morphometric data using a Zeiss VIDAS image analyser. No attempt was made to classify the different types of blood vessels. The morphometric blood vessel parameters estimated were volume density, number per unit area, length per unit volume and mean transverse sectional area. PCNA indices were determined by estimating the percentage frequency of PCNA positive nuclei in basal and spinous strata. Generally, there were significant increases in all PCNA indices and blood vessel parameters between the N group and the different pathological lesions. A highly positive correlation was detected between all PCNA indices and blood vessel parameters. These data suggest that increased vascularity and angiogenesis occur in support of actively proliferating and transforming oral epithelial cells in order to permit growth. PCNA indices and blood vessel parameters may have a potential application as diagnostic and prognostic indicators.