In this case study I am going to represent my work with a boy aged 13, who is, at the first place, included into a psychotherapeutic treatment because of his school phobia. However, in the background of this school phobia, there were separation anxiety, early trauma experiences and the issue of attachment. This writing presents the importance of differential diagnostics when psychotherapeutic treatment with children and adolescents are in focus, as well the fact that in work with children and adolescents, we must be aware of the fact that the development of symptomatology lies in different samples and that is very important to look broader picture in treatment and not to bring conclusions too fast. Psychotherapeutic treatment was held in a continuous manner, 18 months, through 50 meetings. I used the principles of integrative psychotherapy. When choosing methods of my work and choice of interventions, I used theory and approaches od different psychotherapeutic directions, and the psychotherapeutic work with this boy was based on awareness, reparation, and integration of alienated parts of self, strengthening Ego and routing to present day and identity, as well as strengthening of his self-awareness in interaction with other persons. In this essay, the importance of bringing changes in the most important boy’s environments: family and school, together with providing psychotherapeutic help to the boy, is emphasized too.