Sex and gender are understood as two related but separate constructs. Sex refers to the biological and anatomical characteristics of a person, and gender refers primarily to social expectations about the characteristics and behavior of a person according to their assigned sex/gender (expected masculine or feminine traits). Gender identity is defined as a person's internal psychological identification, which may or may not correspond to a person's body or assigned sex. Transgender people are an example of people with gender identities outside of gender binary norms. Summarizing the various definitions, it can be said that transgender people are those whose gender is not aligned with the assigned sex, i.e., whose gender is outside the scope of traditional, socially defined gender roles and norms. Despite greater recognition of people with different gender identities today, many social structures are still very much marked by the gender binary. Therefore, people whose gender identity or expression does not fit into the gender binary are exposed to stereotyping, stigmatization, transphobia, cisgenderism, and unfavorable treatment. Croatian society, which is the social context of this research, is characterized by ambivalent influences on the position of transgender people. Croatia is one of the European Union member states with the most traditional gender norms, and due to the greater visibility of gender nonnormative people, more anti-gender movements have appeared recently. Also, transgender people in Croatia are still often exposed to discriminatory and violent treatment in society. At the same time, the activism of LGBTIQ+ people has significantly contributed to the improvement of social attitudes about transgender people and the realization of certain legal rights. Transgender people in Croatia are protected by anti-discrimination laws, and they have the possibility of accessing legal gender recognition. The theoretical framework of this research is the gender minority stress model by Hendricks and Testa, which is an adaptation of Meyer's minority stress model. The gender minority stress model describes the distal and proximal stressors to which, in addition to common life stressors, transgender and gender-conforming people are exposed. Distal or external stressors include experiences such as gender-related violence, gender-related discrimination, gender-related rejection, and nonaffirmation of gender identity. The second category of minority stressors, proximal or internal stressors, are internalized transphobia, negative expectations (fear of further victimization or discrimination), and concealment of identity. Because of this increased stress, transgender and gender non-conforming people are at increased risk of impaired mental health and well-being. The model also lists stress-relieving factors such as pride in identity, social support, and connecting with other transgender people. What sets this research apart from others in the field of gender minority stress is its focus on positive mental health (flourishing), rather than solely on mental health problems. Previous research in Croatia has investigated certain dimensions of gender minority stress, but none of the studies has covered all dimensions of this model. Also, the focus was mainly on people who approached the gender adjustment process, so those transgender people who did not affirm gender were omitted. Because of that, it is justified to focus on transgender people, regardless of whether they have affirmed gender, as well as on aspects of gender minority stress in the Croatian context that have not been covered so far. Research aim and research questions This research aimed to deepen the understanding of the model of gender minority stress in the Croatian context, based on the experience of transgender people. Therefore, the research aim was to describe distal and proximal stressors of transgender people living in the Republic of Croatia, their coping mechanisms, and their perception of their mental health. The stated goal was operationalized through the following research questions: 1) What distal and proximal stressors are described by transgender people living in the Republic of Croatia? How do the described stressors fit into the gender minority stress model? 2) What ways of coping with stress do transgender people living in the Republic of Croatia use? How do these ways of coping fit into the gender minority stress model? 3) How do transgender people living in the Republic of Croatia perceive their mental health? Methodology Following the research aim and research questions, a qualitative research approach was used. The snowball method was chosen to recruit participants. Participants were reached by contacting NGOs, online via Instagram, and through acquaintances of the researcher. Participants are mostly transgender men and those that affirmed the gender to some extent. They are also mostly younger, Croatian, single, highly educated / currently in the higher education system, and live in urban areas. The self-assessment of the socioeconomic status of most participants is average or slightly better than average. 20 semi-structured interviews (face-to-face or online) were conducted in September and October of 2022. After the interview, the participants completed the sociodemographic characteristics questionnaire and the Croatian version of the Mental Health Continuum-Short Form. The collected data were processed using the process of inductive thematic analysis. The MAXQDA program was used for coding of the data. The data collected through questionnaires were analyzed using methods of descriptive statistics through the SPSS program. Before conducting the research, the approval of the Ethics Committee of the Faculty of Law in Zagreb was obtained. During the collection of data and conducting the analysis, the principles of respecting autonomy, well-being, and non-harm were applied. Participants were informed of all ethical aspects before consenting to participate through the Participant Notice. Before the interview, they signed informed consent. Multiple strategies for ensuring the reliability of research were applied during the design and implementation of the research, in terms of dimensions of credibility, portability, audit ability, and confirmation capabilities. Results The research results are consistent with the theoretical model of gender minority stress, which was the theoretical starting point of this research, and show that transgender people in Croatia experience multiple distal stressors, at the structural, institutional, and interpersonal levels. The most common experiences include nonaffirmation of gender identity, gender-related unsupportive reactions, gender-related discrimination and gender-related victimization, with gender-related victimization least present. Interpersonal minority stressors have been experienced in environments such as the family, the wider environment, and in public institutions, primarily in the healthcare and education system. Due to distal stressors, internalization of negative attitudes about transgenderism, gender concealment, and negative expectations are present as proximal stressors. Transgender people in Croatia use different coping mechanisms at the individual and group levels, some of which are adaptive and some are maladaptive. As the most important ways of coping, participants recognized gender affirmation, inclusion in the trans community, and social support, and it can be assumed that some participants developed resistance to minority stressors. Participants vary according to their experience of mental health, noticing the contribution of minority stressors and impaired emotional well-being and personal growth and development. The highest values are present on the dimension of psychological well-being, and the lowest on the dimension of social well-being. Seven participants have high mental health, eleven of them have moderate mental health, and one participant has low mental health, meaning only a third are flourishing. It can be concluded that minority stress affects the mental health outcomes of transgender people in Croatia, but also that in some mental health is not impaired due to the development of resilience. Given all of the above, it can be concluded that the model of gender minority stress applies to the Croatian context. Conclusion The results indicated the presence of distal and proximal stressors in transgender people in Croatia. In addition, they use multiple coping mechanisms, the most significant of which are gender affirmation and pride, social support, and connection with the transgender community. One can see the contribution of minority stressors, as well as resilience, to mental health outcomes. A third of participants have high mental health, most participants (about half of them) have moderate mental health, and one participant has low mental health. In other words, approximately a third of the participants flourish, which is a slightly higher percentage compared to the student population in Croatia, but a lower percentage than in the general population in other countries. The estimated scientific contribution of the doctoral dissertation is reflected in the verification and more detailed understanding of the model of gender minority stress in the Croatian context, the description of distal and proximal stressors, coping mechanisms and mental health from the perspective of transgender people. The recommendation for future research is to deepen the results of this research, and focus on subgroups underrepresented through this research such as trans women, trans older people, and those from rural areas, as well as people with intersectional identitities identities. Also, other research needs to be more inclusive more inclusive in terms of gender identity. Recommendations for experts and the public are increasing knowledge and sensitizing the public and experts on trans topics, educating the public, experts, and future experts on trans topics, greater adaptation of existing services to people with minority gender identity, providing support to trans people and their loved ones, and interventions aimed at encouraging protective factors or increasing positive mental health.