The objective of this video is to review the development of the external genitalia and to describe our technique for performing male to female vaginoplasty for the transgender woman. In this video, we review the development of the external genitalia for males and females. We then describe the penile inversion vaginoplasty technique that creates a neovagina using a proximal scrotal-perineal flap and a distal pedicled penile skin flap. We perform male-to-female vaginoplasty accounting for the homologous embryologic structures of the male and female external genitalia. With our technique, the neoclitoris is created from the glans of the penis, which developed from the genital tubercle, and would otherwise have developed into a clitoris in a biologic female. This ensures a sensate neoclitoris. The neovestibule is created from the urethra. Both the female vestibule and the male urethra developed from the endodermal lining of the urogenital sinus. The result is a functional neovestibule that provides moisture to the neovagina. Vaginoplasty allows transgender women to have external genitalia that are functional and congruent with their gendered self.