The psychotherapy of perpetrators of domestic violence was created in the 1970s and has been developing as an important area of psychological assistance since then. The article presents a program and individual psychotherapy process based on psychopathology and standards recognized and followed in various countries of the world (USA, Europe, Australia). The first part of the article points to specific and significant areas addressed in the psychotherapy of perpetrators of domestic violence, resulting from the standards used in psychological assistance in this area. The second part contains a description of the therapeutic process as a case study, also depicting the transformation in harmful behaviours of the perpetrator undergoing the therapy. The third part of the article contains the analysis of several areas of transformation in the individual experience of the client and their specificity. The highlighted areas include identity, life history, and interpretation of current events in family relationships. The final part is a discussion of the presented results, with a particular reference to the transformation in identity as the structure indicating in the most powerful way the extent of internalization of the transformation. The conclusions contain several guidelines defining the direction and the need for further research on the degree of internalization of changes occurring during psychotherapy.