Steroid hormones substantially influence brain development, reproduction sexual differentiation and emotion. These effects are mediated by steroid hormone receptors and cofactors, which directly regulate gene expression. Deciphering how and where these transcriptional activators occur in a cell provides the groundwork for elucidating the influence of these small hydrophobic signal molecules on various brain functions. This paper describes some of the recent investigations into the subcellular localization of steroid hormone receptors and cofactors using GFPs and other immunocytochemical methods.