The article examines the forms and directions of interaction between investigators of security agencies and operational units during the pre-trial investigation of criminal offenses related to smuggling. The relevance of the topic is due to the high level of threats posed by smuggling activities in conditions of martial law, as well as the need to increase the effectiveness of countering these manifestations through coordinated interagency cooperation. The purpose of the article is to identify the key tactical and organizational aspects of interaction between the SSU (The Security Service of Ukraine) investigator and other entities involved in criminal proceedings in smuggling cases. It has been established that such interaction covers both procedural (execution of orders, participation in joint investigative (search) activities, creation of investigative and operational groups) and organizational (coordination meetings, planning, information exchange) forms. Examples of effective cooperation with customs authorities, expert institutions, postal operators, and other entities are provided. Typical problems of interaction (insufficient coordination, formal attitude, lack of resources) that require regulatory and managerial solutions are highlighted. The need to improve communication, professional motivation, and organizational coordination between all parties involved in pre-trial investigations is justified in order to ensure a complete and objective determination of the circumstances of smuggling.