AbstractWe have established transgenic mice expressing the Cre recombinase under the control of the anti‐Müllerian hormone (AMH) gene promoter. Cre activity and specificity were evaluated by different means. In AMH‐Cre mice, expression of the Cre recombinase mRNA was confined to the testis and ovary. AMH‐Cre mice were crossed with reporter transgenic lines and the offspring exhibited Cre‐mediated recombination only in the testis and the ovary. In male, histochemical analysis indicated that recombination occured in every Sertoli cells. In female, Cre‐mediated recombination was restricted to granulosa cells, but the protein was not evenly active in every cells. From these results, we conclude that potentially, this transgenic line possessing AMH promoter‐driven expression of the Cre recombinase is a powerful tool to delete genes in Sertoli cells only, in order to study Sertoli cell gene function during mammalian spermatogenesis. genesis 33:114–118, 2002. © 2002 Wiley‐Liss, Inc.