Langerhans cells are dendritic non epithelial cells found in the gingiva. The latest research in immunohistochemistry suggests that they may play an important role in the cellular immune response. The purpose of this quantitative study was to evaluate the number of Langerhans cells in association with gingival inflammation and the use of monoclonal antibodies reacting with two different antigens: T6 and HLA-DR, present on the cell membrane. Results indicate that Langerhans cells are mostly T6+; but HLA-DR appears as a good functional marker. Langerhans cells may play an important role in the cellular immune response to bacterial antigens in moderate inflammation of the gingiva.