Male-biased genes have drawn considerable attention due to their relatively rapid rates of interspecies diversification. These genes are often involved in processes related to reproductive behavior, sexual competition, and gametogenesis. Despite this trend toward rapid evolutionary change, many core molecular pathways underlying spermatogenesis are conserved between Drosophila melanogaster and several mammalian species. Using BLAST search in the database, 22 testis-specific mammalian orthologues of 174 known D. melanogaster male-biased proteins were identified. They are related to a variety of molecular processes. Several also showed association with human male-factor infertility. These genes/proteins may find applications in the diagnosis and treatment of male infertility and the development of novel contraceptives.