It is studied in the article that the problems, arising during the process of the suspect’s and the accused interrogation on criminal cases in the sphere of illicit drugs and psychotropic substances can be and must be considered on the basis of the investigative situation methods. The value of the situational approach in the tactics of the mentioned above persons interrogation consists of consideration and the analysis of situation’s different ways of development but not in the complete following the earlier developed plan. The approach studied allows us to develop algorithms to overcome the problem connected with the refusal from the evidence given by the suspects and the accused in the sphere of illicit drugs and psychotropic substances trafficking. The tactical aspect of the suspect and the accused in the illicit drugs and psychotropic substances trafficking allows distinguishing both his and her actions and tricks in time to correct operations necessary for the investigational steps. The investigator is capable to switch unfavorable circumstances of the investigation info favorable ones using this approach. The possibility to manage the situation when a suspect’s and an accused interrogation on the mentioned cases takes place is one of the most important tasks of the preliminary investigation.