The article discusses the current problems of administrative and legal prevention of the transfer of prohibited items to persons held in institutions of the penal system. The statistical data of the Federal Penitentiary Service of Russia for 2024–2025, law enforcement practice, as well as organizational aspects of correctional institutions' activities to block the channels of entry of prohibited items are analyzed. A comparison is made with the practice of foreign countries. Particular attention is paid to the analysis of legislative changes that came into force at the end of 2023 and their impact on the effectiveness of preventive activities. Based on the conducted research, proposals are formulated to improve the legal regulation and organization of preventive work.