We immunohistochemically evaluated whether oral epithelial cells grown on amniotic membrane (AM) would be an effective biomaterial for reconstructing oral mucosal defects. Oral mucosal epithelial cells from albino rabbits were grown for 2-3 weeks on an AM carrier in a co-culture with 3T3 fibroblasts. The rabbits' oral mucosal defects were reconstructed by autologous transplantation of the oral epithelial sheets. The oral epithelial sheets and reconstructed tissues were then examined histologically and immunohistochemically. After 2-3 weeks of culture, the rabbit oral mucosal epithelial cells developed 5-7 layers of stratification on the AM. Immunohistochemistry revealed that they expressed keratins 4/13, integrin alpha 6, alpha 5 chain and collagen type III, but not keratins 1/10. The transplanted sheets attached to the mucosal defects, and AM fragments disappeared from the transplant area. Immunohistochemical patterns revealed properties of the mucous membrane and basement membrane components in the reconstructed epithelia. The results of this experiment showed that the AM-cultured oral epithelial sheets resulted in mucosa-like differentiation, and adhered to the mucosal defects. Therefore, AM-cultured oral epithelial sheets might be a useful biomaterial for oral mucosal reconstruction.