The functions of the pituitary hormones have been relatively well studied; however, understanding the regulation of their synthesis and release have been an ongoing subject of intense research. This review provides an overview of the pituitary cell types and their hormone products. Current understanding of the expression and regulation of the pituitary hormone genes, control of the synthesis and release of the corresponding hormones, and developmental changes are reviewed. This review concludes with a discussion of several of these genes and the genetic disorders with which they are associated.