Potential ethical problems of psychotherapeutic treatments are discussed with regard to the Principles of Biomedical Ethics (Beauchamp and Childress 2019). After firstly debating the relationship between ethical problems and treatment error, the possible ethical problems in psychotherapeutic treatment are discussed, especially ethical problems in treatment planning, ethical dilemmas in informed consent and the prevailing economic conditions of treatment. Furthermore, the ethical requirements of the therapist are considered; especially treatment errors and their possible ethical implications are discussed. In addition, consideration is also given to therapist abuse and its consequences. Finally, ethical consequences for therapeutic practice are mentioned.