We present a novel, simple and straightforward method to obtain mouse bone marrow-derived dendritic cells (DC) from C57Bl/6 CD4/CD8(-/-) double knock-out mice. This new method, involving culture of bone marrow cells in medium supplemented with Interleukin 4 and Granulocyte-Macrophage Colony-Stimulating Factor, does not involve negative immunodepletion of CD4+ and CD8+ populations, or extensive prior manipulations of the starting population. The resulting, loosely adherent cell population, exhibited the morphological characteristics and typical surface markers of DCs, and were endowed with the functional activities characteristic of bone marrow-derived DCs of wild-type mice. Interestingly, LCMV GP33-41 peptide-loaded CD4/CD8(-/-) DCs were efficiently lysed by peptide-specific activated CTLs in vitro. Furthermore, these peptide-loaded CD4/CD8(-/-) DCs induced a peptide-specific CTL response upon immunization of wild-type C57Bl/6 mice.