The problem of transsexualism is often marginalised both in medical and psychological practice. This results in mental and physical self-injuries, as well as suicide attempts and suicides of patients. Early diagnosis and medical assistance may significantly prevent it. However, for this to be possible, medical personnel needs to possess adequate knowledge of the diagnosis, treatment and management of patients affected by this affliction. The aim of the study is an attempt to verify the knowledge of the subject of transsexualism of family doctors and residents. To this end, 90 questionnaires, correctly completed by these doctors, were analysed. All the questions were meant to verify the knowledge of the diagnosis and treatment of transsexualism. The obtained results led to the following conclusions: 1. All the respondents confirmed the lack of sufficient knowledge of transsexualism and the need to deepen it. 2. The concepts of transsexualism, transvestitism, transgenderism, crossdressing, were often confused by respondents and wrongly regarded as synonyms. 3. It is necessary to identify the problem at an early stage and to provide these patients with the assistance of interdisciplinary teams.