Purpose: analysis of the category "ground for initiating a criminal case" and determination of the criteria for the presence of grounds for initiating criminal cases on crimes related to narcot-ic drugs in typical situations of obtaining initial information on the signs of drug crimes. Research methods: dialectical and activity approaches, methods of system analysis, study of investigative practice, expert assessments were used. Conclusions: assessment of qualitative and quantitative characteristics of the initial infor-mation contained in statements and reports on drug-related crimes increases the probability of the investigator's correct resolution of the issue of initiating a criminal case. Scientific and practical significance: a comprehensive informational characteristic of the requirement of “sufficiency of data” in the design of the ground for initiating a criminal case for drug-related crimes has been developed.