We have used monoclonal antibodies to study the expression of calgranulins by keratinocytes in inflammatory dermatoses. Calgranulins are intracellular calcium binding proteins which have inflammatory cytokine activity and are composed of at least two different chains, calgranulin A and B. Antibody CF 145 and CF 557 identify calgranulin A and B, respectively. MAC 387 recognizes a molecule probably containing both calgranulins. Keratinocytes in normal skin did not contain these molecules. The keratinocytes in 52 cases of different inflammatory dermatoses showed expression of both calgranulin chains in lesional but not in non-lesional skin. Keratinocytes in inflammatory dermatoses therefore express an intracellular calcium binding protein which has cytokine activity.