The purpose of this study was to demonstrate immunohistochemically the localization and distribution of human beta-defensin-2 (HBD-2), a peptide with antimicrobial activity, in oral carcinoma tissues. Tissue samples were embedded in paraffin, and HBD-2 was immunostained by the streptavidin-biotin coupled peroxidase method. Cancer cells in the cornified region of well differentiated squamous cell carcinomas were stained intensely. Stained cancer cells detected by anti-HBD-2 antibody were scattered among the cells of the non-cornified region.