The aim of this study was to investigate the effect of cinnamaldehyde (CIN) on 7, 12-Dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis on hamster cheek pouch (HCP) mucosa. Sixty male golden Syrian hamsters were selected and randomly divided into six equal groups. The hamsters of groups I, II and III received no treatment, DMBA and CIN respectively, for 16 weeks. Groups IV and V were handled as group II and concomitantly treated with CIN for the same period and additionally group V received CIN for other 16 weeks after the stoppage of DMBA application. Group VI hamsters were handled as group III and additionally received DMBA for other 16 weeks after the stoppage of CIN supplementation. Hamsters of each group were euthanized according to the time schedule. The buccal pouches were excised and prepared for PDGF immunohistochemical reactivity. The highest reaction for this protein was detected at the epithelium and underlying connective tissue in fibroblasts and endothelial cells of group II HCP that was subjected to DMBA for 16 weeks. Group III which received only CIN, revealed the least expression of PDGF-BB in epithelial and connective tissue cells .From the previous results, it can be concluded that CIN has a beneficial role as a chemopreventive agent as it causes regression of cancer progression as it showed marked antiangiogenic effect.