Abstract: The data of the study of the relationship between the components of psychological well-being and existential fulfillment in late adolescence are presented. It was suggested and proved that the first fundamental existential motivation (according to the methodology of V.B. Shumsky, E.M. Ukolova, E.N. Osin, Ya.D. Lupandina "Diagnostics of existential fulfillment") concerning the possibility of being in the world is significantly related to self-acceptance and competence. The second fundamental existential motivation concerning the value of life is significantly related to self-acceptance and positive relationships. The third fundamental existential motivation concerning self-worth is significantly related to self-acceptance and personal growth. The fourth fundamental existential motivation concerning meaning is significantly related to life goals and autonomy. The study sample consisted of boys and girls aged 17 to 25 years in the number of 82 people, 41 of them boys and 41 girls. In the course of the study, the goal was achieved, namely, significant connections were revealed between the components of such constructs as psychological well-being and existential fulfillment. We have made the following conclusions: 1) Respondents with a high level of psychological well-being were guaranteed to have a high level of existential fulfillment. However, respondents with a high level of psychological well-being did not always have a high level of existential fulfillment. 2) The component of psychological well-being "self-acceptance" demonstrated the most significant relationship with the components of existential fulfillment (fundamental existential motivations) at the significance level of p≤0.01. The practical significance of the work lies in the fact that the results of the study can be applied in the framework of existential psychotherapy, as well as in the analysis of factors that affect the psychological well-being of a person.