Abstract : This paper explores the role of medicine in the regulation of legal gender recognition for trans and gender diverse people in France and Italy. I focus on the processes that led the two countries to establish for the first time a procedure for legal gender change in the 1980s/1990s. Despite the differences, both in France and in Italy medical knowledge and technologies were embedded in the procedures for legal gender change and health professionals took a role as gatekeepers to gender recognition. The medicalization of legal gender recognition, I argue, was part of the deploying of a bio-political apparatus that Aim :ed at regulating and controlling “gender transitions” through regulation and normalization rather then through repression.