The article discusses the reasons for the adoption of the Unified Convention of 1961, which was to create a unified international system for controlling the circulation of these dangerous substances. It is shown that the authors of the document focused on issues of international trade, control over the circulation of these substances and terminology. A feature of the document was the presence in it of four lists of narcotic substances, depending on the degree of their danger and the negative impact on human health. There are three reasons for the relevance of the research topic. First, the need to combat the spread of drugs in Ukrainian society by increasing the effectiveness of measures to combat illicit trafficking in such drugs. Today in Ukraine there is a steady trend of increasing the number of drug addicts, which affects the level of criminogenicity of society. Secondly, at the present stage, drug crime is becoming more professional, significant financial resources allow drug addiction to undermine the economy and political foundations of the state. In such circumstances, there is a situation where any state alone is unable to counter drug trafficking. Based on this, there is a need for close international cooperation between different states in order to combat such dangerous phenomena. Third, the 1961 Single Convention on Narcotic Drugs played an important role in uniting many countries in the fight against drug crime. The interest in this international treaty is not accidental, due to the fact that the Convention has become the basis of legal policy of many countries aimed at combating drug trafficking, so the content of this document needs more detailed study. At the same time, the need for Ukraine’s participation in international cooperation is exacerbated by the country’s location in the middle of Europe, which leads to the use of its territory as one of the ways of drug trafficking. Key words: international treaty, UN convention, narcotic drugs, legal liability, quantitative indicators.