Legal cases are situations that most specialists do not like and see them as a challenge to their practice. However, being appointed as a legal expert is almost inevitable. Therefore, legal experts and especially psychiatrists should have enough knowledge in order to evaluate the forensic cases appropriately. Psychiatrists need to be careful on certain legal issues. In this presentation, some important points that psychiatrists should be aware of, were emphasized. Mental disorders may have a course of improvement or worsening of the symptoms and might become chronic. (e.g. The criminal responsibility is effected by whether patients with schizophrenia had a psychotic episode or not at the time of crime, slight referential perceptions, or some thoughts not powerful as delusions may not be detected during psychiatric evaluation, patients with borderline personality disorders may have micro psychotic episodes effecting criminal responsibility). Patients should provide the legal expert with information about their past diagnosis and treatments, etc. If the patients withhold information, this situation can have an effect on the case process and this kind of can be misleading for the legal expert. As a general view, if the civil court asks for a detailed epicrisis without the consent of the person, this may not be provided due to it being confidential information. So the consent of the patient should be provided. If it is a criminal court, the epicrisis should be presented even without the consent of the patient. Otherwise, the judge may accuse the expert for preventing the course of justice and the expert can be sued for a compensation case). All possible information sources should be evaluated (information from the person of interest, relatives acquaintances of the person should be gathered and if necessary, social evaluation should be asked from the social services). The expert should answer all the questions of the judge or the prosecutor, otherwise the expert may be asked to give another expert opinion again. Any psychometric measurements such as electroencephalography (EEG), brain imaging (MRI, etc.) should also be written on the forensic expert opinion report. If necessary, personal and family history, personality traits, upbringing and cultural features should also be evaluated and reported. All findings and evaluation results should be discussed first and eventually evaluated on the conclusion part on forensic expert opinion report. Although legal expert is not the judge and does not give penalty, etc., but should examine the case file carefully. The report given is a forensic expert opinion, if the expert does not have a solid opinion, the patient can be referred to another expert or a medical legal institute. In the light of the existing data, if an expert opinion is not formed, this should be stated properly with its reasons.