Since the discovery of the testis-determining gene SRY in the early 1990s, rapid progress has been made in illuminating the genetic pathways for testis cord morphogenesis. Research on fetal testis cord development has largely focused on two key areas – testis determination and testis cord establishment. In the first of these events, expression of SRY in the XY gonad triggers a signaling cascade, which establishes the Sertoli cell lineage and thus secures testis identity. The second event, testis cord establishment, relies upon expansion of the Sertoli cell population as well as the migration of cells from the mesonephros. In this review, we aim to discuss these two stages of testis cord formation as well as suggest the existence of a third phase in this fascinating process – the need for further maintenance of the testis cords during the period between testis cord establishment and birth