Health care of individuals who experience their gender not, not completely and/or not continuously in line with their sex assigned at birth has been organized for a long time in an area of conflict between the right for self-determination of transgender individuals and the fear of incorrect decisions among mental health professionals. The German Standards for the Treatment and Diagnostic Assessment of Transsexuals, published in 1997, were an attempt to regulate this area of conflicts within the German health system. Meanwhile, in view of the seventh version of the international Standards of Care published by the World Professional Association for Transgender Health (WPATH) as well as based upon recent judgments of the Federal Constitutional Court in Germany, the German standards must be exigently revised. In consequence, the Deutsche Gesellschaft für Sexualforschung (DGfS, German Society for Sex Research) has begun to substitute the above-mentioned standards with an evidence-based guideline aiming at an improvement of the service quality. This article introduces the history of transgender care in Germany, describes the background and the procedures of the current guideline development, and discusses how participatory approaches might improve the health care situation for transgender peeople in Germany.