The scientific article examines issues related to identifying the problems of detecting the illegal sale of narcotic drugs, psychotropic substances, their analogues and precursors. A number of problems related to the detection by law enforcement officers of the illegal sale of narcotic drugs have been clarified and outlined. A number of means and measures that organized criminal groups use for the possibility of illegal sale of narcotic drugs have also been established, and they have been considered.
 It has been established that drug criminals constantly improve the methods of illegal sale of narcotic drugs, psychotropic substances, their analogues and precursors, using new means and tools. This, in turn, gives rise to problems of detecting illegal drug sales.
 An inseparable part of modern organized criminal groups involved in the illegal sale of narcotic drugs is the conspiracy of illegal activities, the use of various mechanisms to ensure against direct contact with buyer during their transfer. The members of some criminal groups do not know the members of other criminal groups, but contact only those with whom they work continuously. Such organized criminal groups have an extensive and complex structure with a strict division of roles, high discipline, and hierarchy. Conspiracy, high mobility, the availability of means of communication, a significant level of organization, as well as establishing cooperation and reducing competition between other criminal groups complicates the possibilities of detecting narcotics during illegal transportation.
 It was found that a number of problems in detecting the illegal distribution of narcotic drugs depend not only on the constant ingenuity and improvement of the criminal activity of criminals, but also on the continuous updating of the knowledge of law enforcement officers about the peculiarities of such activity and their professionalism. And therefore consideration of this problem is a necessary condition for effective detection of illegal sale of narcotics.