The study of the external genitalia is divided into 2 developmental stages: the formation and growth of a bipotential genital tubercle (GT) and the sexual differentiation of the male and female GT. The sexually dimorphic processes, which occur during the second part of GT differentiation, are suggested to be governed by androgen signaling and more recently crosstalk with other signaling factors. The process of elucidating the regulatory mechanisms of hormone signaling towards other signaling networks in the GT is still in its early stages. Nevertheless, it is becoming a productive area of research. This review summarizes various studies on the development of the murine GT and the defining characteristics of a masculinized GT and presents the different signaling pathways possibly involved during masculinization.