In this study, we report the immunohistochemical localization of versican in healthy porcine gingival epithelia. The monoclonal antibody (mAb), 5D5, specifically recognizes core proteins of large chondroitin sulphate proteoglycans such as versican, neurocan and brevican, but not the core protein of aggrecan. Because neurocan and brevican appear to be specific to nervous tissue, the large chondroitin sulphate proteoglycans examined in this study is most likely versican. In the keratinized layer of the attached gingival epithelium, the basal and spinous cell surfaces showed intense staining for mAb 5D5. In the parakeratinized layer of the sulcus epithelium, the localization was restricted to the basal and lower spinous layers. In the junctional epithelium, intense staining was observed in one or two cell layers near the enamel surface. Immunoelectron microscopy revealed high-density depositions of 5D5 immunoreactivity on epithelial cell surfaces. At the enamel surface, 5D5 immunoreactivity was localized to the dental cuticle of the junctional epithelium but was not present in the internal basal lamina. These results suggest that versican, a large chondroitin sulphate proteoglycan, is involved in epithelial differentiation and downgrowth.