Cyclosporine is widely used as an immunosuppressive agent after solid organ transplantation. Limited data are available on the modulation of human dendritic cells by cyclosporine. We investigated the effects of cyclosporine on the phenotype and function of human dendritic cell (DC) subsets. DCs were isolated from peripheral blood using magnetic bead-conjugated antibodies. Cyclosporine did not alter the ability of myeloid and plasmacytoid dendritic cells to take up antigens. Expression of the co-stimulatory molecule CD80 but not CD86 increased on both DC subsets when stimulated with cyclosporine. The ability of cyclosporine treated myeloid DCs to stimulate proliferation of allogenic PBMC was significantly reduced. Similarly, stimulation of memory CD8+ T cells by dendritic cells was impaired by cyclosporine pretreatment. In conclusion, cyclosporine differentially alters function and phenotype of myeloid dendritic cells leading to a partially impaired capacity to stimulate allogenic and autologous T cells.