The problematic issues of using a polygraph in criminal proceedings, which are relevant for many countries, are considered. Based on the analysis of judicial practice and publications of recent years, including foreign ones, the solution of the following issues is proposed: what should be the form of application of polygraph in criminal proceedings (definition of investigative action); what is the basis for the use of a polygraph in criminal proceedings; who can be the direct authorized subject of the polygraph application; what should be the method of using a polygraph in criminal proceedings. Attention is drawn to the importance of resolving these issues for investigative and judicial practice in accordance with the laws of a country. It is noted that the use of a polygraph requires the use of special knowledge in the field of psychology. Therefore, the use of a polygraph in criminal proceedings is possible only during the psychological examination of a person in order to obtain indicative information to solve the tasks set by the initiator of the examination. It is substantiated that the basis for the use of a polygraph is the nature of the tasks of the initiator of the examination in the absence of medical contraindications in the subject, as well as his written consent to the survey using a polygraph. Only a psychologist with a polygraph operator as a technical assistant can be the subject of the polygraph application and evaluation of the test results. The method of con-ducting a human study using a polygraph expert determines independently, based on the tasks formulated by the initiator of the examination. It is noted that a separate study requires the preparation of a criminal psychological examination using a polygraph, defining its tasks, methods of conducting and evaluating its results. The solution of these problems in different countries will depend on the specifics of national legislation