Standardizing Sex traces the emergence of trans medicine in Scandinavia in the twentieth century, exploring the construction and negotiation of medical expertise among medical professionals, patients, and activists in the media and government bureaucracy. The book combines the author’s analysis of medical records and other archival sources with oral history interviews with former patients, activists, doctors, psychologists, and civil servants. Physician-historian Ketil Slagstad uses the Scandinavian story of sex reassignment to anchor not only the role of the state but also bureaucracy and social rights. Scandinavian countries, he shows, played a foundational role in the emergence of trans medicine internationally. As a result, Standardizing Sex tells a transnational history of medicine that sheds light on a set of relations and problems that continue to impact discussions of trans medicine and trans rights around the world.