Methods used in the evaluation of psychotherapy effectiveness in treatment of mental and behavioural disorders in children and adolescents are analysed to discuss possible incongruity of their results. Method. The accessible reports and meta-analyses of studies on psychotherapy results are presented. The criteria of qualification to the treatment, designs of research programmes and the methods of results evaluation are considered. Results. The reports on the psychotherapy efficacy in the treatment of children and adolescents are - as expected - scarce. They concern mainly behaviour, anxiety and depressive disorders. Classifications for treatment are not homogeneous. The treatment results are usually assessed in rather short follow-up periods. Studies on behaviour- cognitive therapy delivered on individual, group and family basis dominate. Conclusions. 1. Research on psychotherapy in treatment of children and adolescent are carried on, however there is only few publications on this topic. 2. The most frequent aim of the studies published is the effectiveness of psychotherapy. 3. There are no clear-cut conclusions on effects of psychotherapy in children and adolescents, however the critical meta-analyses point out its effectiveness and sound reasons for recommendation. 4. The research on the significance of mediating aims slightly confirm the hypotheses on pathogenesis of emotional disturbances in children and adolescents. 5. The research on psychotherapy outcome mediators and moderators looks promising.