The main goal of this thesis was to determine the relationship between the use of stress-coping strategies and suicidality in adolescents, taking a look at gender differences and the prevalence of suicidality in adolescents. The implementation of this thesis was realized based on the use of data from the project "Testing 5c model of positive youth development: traditional and digital mobile measurement (P.R.O.T.E.C.T.)” by the Faculty of Education and Rehabilitation in Zagreb. For the purposes of this thesis, the results collected in the second point of the research, during the 2022./23. school year, were used. 3261 second grade high school students participated in this point of research and for the purposes of the thesis, a sub-sample of 593 second grade high school students from the Varaždin County has been selected. The main constructs of this thesis were collected by the subscale of the Developmental Assets: A Profile of Your Youth (Search Institute, 2018) that examines symptoms of suicidality and by the Shortened version of the Stress-coping questionnaire (Hudek-Knežević, Krapić, & Kardum, 2006) that examines the use of stress-coping strategies. General information about the participants was collected using a demographic data scale. The results of the research showed that 69,8% of adolescents do not express any suicidal symptoms, while 30,2% of them, i.e. almost one third, express certain suicidal symptomatology. Furthermore, 21,9% of them reported self-harm, 19,7% reported seriously considering the possibility of committing suicide, 12,8% had made a plan to commit suicide, and 6,2% had attempted suicide. The results of the conducted chi-square test show a statistically significant difference in all symptoms of suicidality in relation to the gender of the participants. A statistically significant difference between young men, women and adolescents who answered the gender-related question that they would rather not reveal it was observed on the part of self-harm, considering the possibility of committing suicide, making a suicide plan and attempting suicide, although the highest presence of all suicidal symptoms is recorded in adolescents who preferred not to say their gender, taking into account the better representativeness of the sub-sample, it is concluded that it is still the highest within young women and therefore the lowest in young men. Regarding gender differences in relation to stress-coping strategies, the results of the t-test showed a statistically significant difference on the subscale of strategies focused on emotions in relation to the female gender of the participants, i.e. it turned out that young women use the mentioned strategies more often. In the subscales of problem-oriented strategies and avoidance coping strategies, no statistically significant difference was found in relation to gender. Using Spearman's correlation coefficient, data were obtained on differences in stress-coping strategies in adolescents regarding the presence of suicidal symptoms. The obtained data indicate a statistically significant, negative and low correlation between problem-oriented strategies and the presence of suicidal symptoms, also, a statistically significant, low and positive correlation between the use of avoidance coping strategies and the presence of suicidal symptoms, while the relationship between emotion-oriented strategies and the presence of suicidal symptoms is not statistically significant. This work is significant for further planning of science-based preventive and treatment interventions for adolescent mental health problems (with an emphasis on the school environment), as well as for empowering young people to develop adaptive stress-coping strategies.