The study presents modern approaches to the prevention of deviant behaviour used by the psychological service. The relevance of this subject matter is due to the rapid spread of deviant behaviour among adolescents and young adults. The purpose of the study is to analyse the features of the psychological service in work with persons with deviant behaviour. The paper uses theoretical methods of analysis of the research problem, based on which the prospect of further research in the empirical aspect is highlighted. In accordance with the tasks set, the study analysed the main aspects and objectives of the modern psychological service. Features of deviant behaviour among adolescents and young people and its main causes are highlighted. Current approaches to preventing the spread and reduction of deviant behaviour in the work of psychological services are described. The theoretical study revealed that modern approaches to the prevention of deviant behaviour, operated by the psychological service, are described by the presence of primary theoretical knowledge about the features of deviant behaviour in its employees, in particular, the causes and factors of its occurrence. The orientation of preventive work towards elimination and prevention of deviant behaviour within the tasks and competences of the psychological service is substantiated. It is indicated that taking into account the theoretical foundations of the concept of deviant behaviour, employees of the psychological service develop a plan for providing psychological assistance, which calls for systematic, phased preventive work. The need to use modern methods of preventive approaches, including training sessions, the use of information technology and psychological art therapy techniques, has been confirmed. This approach, identified as a result of theoretical research, will ensure the effectiveness of preventive work of the psychological service towards prevention of deviant behaviour