Abstract: The subject of the research is the motivational readiness for professional self-determination of adolescents with deviant behavior. The work is aimed at studying peculiarities of motivational readiness for professional self-determination of deviant adolescents and justifying that it is possible to develop it in the process of psychological and pedagogical assistance. The author of the article describes the social environment (objective and subjective elements) in which a deviant adolescent grows up and concludes that such environment has certain deficiencies and therefore has a negative influence on professional self-determination of adolescents with deviant behavior. The author emphasizes the importance of motivatinal readiness for a successful professional choice as the component of psychological readiness for developing a professional self-identity. The author analyzes psychoogical researches on the motivational sphere of deviant adolescents as well as peculiarities of their motivational readiness for professional self-determination. The author outlines the main disturbances of the motivational development of deviant adolescents including the lack of self-reflection and conflicting motives, the prevailing role of the motive to avoid failure and the motive of constraint, suppressed safety needs, the needs for freedom and group membership. This leads to the lack of understanding and dispersion of professional interests, lack of independence in choosing a majo and limited motives to make a professional choice. The present article presents the results of the author's research of motivational readiness of deviant adolescents for professional self-deterination. The research was carried out at the educational center for children and adolescents with deviant behavior 'Becoming' in the Mari El Republic. The following groups of methods were used by the author to achieve the targets and complete the tasks of the research: theoretical analysis of the academic literature on the matter; methods of psychological diagnostics such as tests and questionnaries; methods of psychological and pedagogical assistance such as trainings, group discussions, role and business games and psychological counseling; statistical treatment, analysis and generalization of the results. The results of the research have demonstrated the lack of established values of deviant adolescents  in the processes of personal interaction and building personal plas compared to their peers from general academic schools, prevailing external motivation towards professional activity such as economic reward for labour, attempts to avoid punishment or critics and the motive to avoid failure in their activity. The author also describes the details of psychological and pedagogical assistance in developing motivational readiness for professional self-determination of deviant adolescents. The article presents the results of the final diagnostics that prove the author's program of psychological and pedagogical assistance to be efficient.