Currently, some of the most widely discussed, both in medical circles and in society as a whole, are issues related to the Transsexualism phenomenon. This interest is due to a sharp increase in the number of persons applying for gender reassignment, the exclusion of this pathology from the class of mental disorders and disorders of behavior in the International Classification of Diseases of the 11th revision, difficulties in differential diagnosis with other mental diseases, a number of ethical problems and imperfection of the organizational and legal aspects of care for such patients. The purpose of this article is to summarize information concerning the health, social and legal aspects of transsexualism (gender incongruence). Materials and methods. This review analyzed more than 60 foreign and domestic sources, included in the review the most influential works in the field of sexology, psychiatry, regulations related to the regulation of the gender change process, official materials of the World Health Organization and the American Psychiatric Association, as well as Standards of medical care compiled by the World Professional Association on Transgender Health. As a result of the review, the place of transsexualism is shown in the new International Classification of Diseases, the relationship with mental disorders, modern data on prevalence, therapeutic approaches and regulatory aspects of gender change are presented. The need to continue research in this area on large samples of people with disorders of sexual identification (gender incongruence), optimization of diagnostic and therapeutic care, this category of persons, as well as the development of uniform standards for diagnosis, therapy and the provision of socio-rehabilitation measures is indicated.