Decidual stromal cells (DSC) constitute the most abundant population in normal human decidua together with leukocytes. Both populations may be involved in the immunological role of the decidua by favoring gestational functions, participating in physiological mechanisms to eliminate the fetus, or providing local defense against infection. Using flow cytometry, we investigated whether different cytokines modulate the expression on cultured DSC of antigen-presenting molecules. The treatment with IFNgamma or IL-1beta enhanced the expression of CD54. The percentage of expression of HLA-DR was enhanced by IL-1beta treatment but was not modified by IFNgamma. The expression of CD80 and CD86 was enhanced by IFNgamma treatment but was not modified by IL-1beta; the expression of CD86 and HLA-DR was reduced by TGFbeta1 treatment. The response of DSC and dendritic cells to these cytokines appears to be similar, suggesting a phenotypic and functional relationship between these cell types.