The aim of the study is to reveal the essence, structure and functions of the ability selfdisclosure mechanism in adolescents. The study is based on existential humanistic ideas about the inner content and self-worth of a person (A. Langle, C. Rogers), approaches of metacognitive psychology, revealing the resources of cognitive processes self-organization in relation to their personality and activities (M. Kashapov, A. Karpov ), ideas about the ability selfdisclosure by V. Chernyavskaya. The main empirical methods were psychodiagnostic, survey methods, self-description methods, comparative method, and modeling. Sample is represented by schoolchildren studying in grades from 9 to 11 in Moscow, the Moscow region and Vladivostok. A new problem of discovering the internal mechanism, which determines the inclusion of the personality's ideas about their own abilities in the self-concept structure, has been solved. The mechanism of ability self-disclosure is justified as a process of ordering the subjective experience associated with the implementation of abilities for a certain type of activity. The structure, content and functions of the ability self-disclosure mechanism in adolescents are revealed. The structure is represented by a system of interrelated elements. These are existential fulfillment, which creates the basis for self-acceptance and adequate formation of a person's self-image; metacognitive qualities that self-organize internal resources by gaining knowledge about the features of their cognitive processes and reflecting relationships with the world and with oneself. The influence of the ability self-disclosure mechanism on academic performance is shown. The mechanism determines the relationship between academic performance and the cognitive interests of a student. The correlation between the relationship of parents to an adolescent and the inclusion of ideas about own abilities in the structure of personality self-concept are revealed. The experience of self-acceptance, self-worth, the meaning of life, satisfaction is mediated by internal dialogue, which contains the internalized attitude of parents to adolescents. It has been determined that the parent role distribution (an adoptive mother and a directive father) develops the ability self-disclosure mechanism. The connection of the adolescent's opinion about what teachers and the reference group think about own abilities with the content of his self-concept is highlighted. It was revealed that the action of the ability self-disclosure mechanism is associated with the processing the information from others about own abilities, its subsequent differentiation and embedding it into the self-concept structure of an adolescent. The data obtained can be used in teachers and psychologists' work to develop psychological and pedagogical programs aimed at improving academic performance; in developing approaches to individual counseling of adolescents, their parents and teachers; in professional self-determination, vocational guidance of high school students, diagnostics of the ability selfdisclosure mechanisms and their development.