DMRT1 (Doublesex and Mab-3 related transcription factor-1) is an evolutionarily conserved transcription factor that is essential to mammalian testis differentiation, gamete maturation, and fertility. Its requirement for gamete maturation and testis-specific location suggest compounds that block DMRT1 function, by disrupting its ability to bind DNA, will reversibly arrest spermatogenesis and thereby represent new potential male contraceptives. Biochemical and cell-based assays are being developed to identify novel small molecules that disrupt the interaction between DMRT1 and its DNA binding element. Such compounds will then be evaluated using whole animal approaches to determine their effects on spermatogenesis and fertility. Studies are also underway to identify genes that are direct targets of DMRT1’s transcriptional activity, as a means to reveal new candidates for contraceptive development.