Ad4BP/SF-1 (adrenal4 binding protein/steroidogenic factor-1[NR5A1]) is an essential nuclear receptor required for animal reproduction and endocrine regulation. The present study reports on monoclonal antibodies (MAbs) directed against mouse Ad4BP/SF-1, which were produced by the hybridization of mouse myeloma cells with lymph node cells of an immunized rat. The produced MAbs reacted with both recombinant and endogenous Ad4BP/SF-1. These MAbs will be useful in immunolocalization and immunoblotting experiments conducted on different tissue types to determine the levels of expression of Ad4BP/SF-1 throughout development, as well as further analyses of the biological function and cellular dynamics of this protein.