The article is devoted to the consideration of the procedure for investigating crimes of a terrorist nature, identifying the features of conducting both individual investigative actions at various stages of the preliminary investigation, and their complex, as well as carrying out the necessary operational-search measures. When describing the procedure for carrying out the necessary investigative and other procedural actions based on the materials of the audit, as well as during the preliminary investigation in criminal cases of a terrorist orientation, the author analyzes the norms of the current Criminal Procedure Code of the Russian Federation and investigative practice. The criminal procedural problems arising in the investigation of crimes of this category are singled out, as well as the author's proposals for their solution. The content of the article has a practical orientation. The article uses the legal provisions of various legal sciences: criminal procedure, criminalistics, the theory of operational-search activity. When writing the article, empirical and theoretical methods of cognition were used, such as analysis, synthesis, observation, and others, general scientific and special methods. The scientific novelty of the article lies in the fact that the author, based on the study and analysis of investigative practice in the investigation of criminal cases of a terrorist orientation by the Federal Security Service of the Russian Federation, highlights the investigative-tactical and criminal procedural features of the preliminary investigation in criminal cases of a terrorist orientation. They can be applied both during the investigation as a whole, and in terms of tactics, procedural order, and the production of individual investigative actions. The problems arising at the practical level during the investigation of these criminal cases are indicated. In the article, the author draws attention to the fact that for effective, high-quality and quick investigation of criminal cases of this category, investigators need to carefully plan the investigation of both the criminal case as a whole and individual investigative and other procedural actions. The author also emphasizes the role of the investigator in assessing the materials of the pre-investigation check and in carrying out certain investigative actions at the initial stage of the investigation. Based on the study of practice, specific recommendations have been developed for choosing the optimal solution to emerging problems.