While psychiatry is engaged in deconstructing the category of "transsexuality," this paper questions the ability of sociology to account for the transgender issue from a non-medical standpoint. Unlike approaches that regard transgender practices as a transgression of the anthropological norms of sexual differentiation or that describe in an interactionist way the associations necessary for the existence of these social practices, this paper rather considers transsexualism as "a gender technology." By this we understand regarding the production of gender identification and gendered bodies as the exercise of a social relationship of power through the imposition of a necessary difference between masculine and feminine. Offering a rereading of nearly one hundred years of medicalization of transgender behaviors and controversies, the paper shows how this technology has historically produced normative effects on bodies and, on the other hand, the capacity for transgender people to transform gender norms through the formation of a cultural movement aimed at denaturalizing, detraditionalizing, and reassigning meaning to gender identification. In conclusion, this paper questions the ability of sociology to account for the gender identification process itself if it cannot be reduced either to biological determinism or cultural determinism. It includes a discussion on the relevance of the concept of "gender identification career" to describe not only "deviant" life stories but the very process of gendered individuation itself.