Physician-assisted suicide (PAS), which is currently the subject of intense and controversial discussion in medical ethics, is barely discussed in psychiatry, albeit there are already dementia patients in Germany and other European countries who end their own lives with the assistance of physicians. Based on the finding that patients who ask for medical assistance in suicide often have in mind the loss of their mental capacity, we submit PAS to an ethical analysis and put it into a broader context of patient autonomy at the end of life. In doing so, we point to advance care planning, through which the patient autonomy of the person concerned can be supported as well as respected in later stages of the disease. If patients adhere to their autonomous wish for PAS, physicians find themselves in an ethical dilemma. A further tabooing of the topic, however, does not provide a solution; rather, an open societal and professional ethical discussion and regulation are essential.