Transgender people who experience serious mental illness represent a uniquely vulnerable population. Because of limited research, however, recommendations for treating this population are scarce. In this article, the authors describe the challenge of recognizing gender dysphoria in people with serious mental illness. They then discuss why existing evidence and clinical experience support provision of gender-affirming medical and surgical treatments for transgender people who have serious mental illness and also demonstrate capacity to make informed medical decisions. More research is needed to develop evidence-based treatments and programs for transgender people with serious mental illness.. Login at top right hand side of page using your MPFT NHS OpenAthens for full text. details.