We evaluated the ability of lactic acid bacteria, Weissella cibaria, isolated from the oral cavity to adhere to epithelial cells. W cibaria efficiently adhered to KB cells and HeLa cells. In addition, W. cibaria efficiently adhered to Fusobacterium nucleatum. But the adhesiveness of W. cibaria disappeared upon exposure to LiCl or pronase, suggesting that the S-layer proteins of W. cibaria mediated the adhesiveness. The molecular mass of the S-layer proteins extracted from W cibaria was approximately 50 kDa. When W. cibaria strains were washed with 0.45% saline, the bacteria were efficiently adhered to the epithelial cells. In conclusion, W. cibaria has the ability to adhere to epithelial cells through the S-layer proteins.