At turning points in the history of the development of any state, the underworld is noticeably transformed. During periods of political destabilization, crisis phenomena in the socio-economic, cultural spheres of society, the crime situation in the country, as a rule, worsens. At the same time, during the collapse of the statehood foundations, the criminal world not only transforms, but changes the vector of its development. Such a period in the history of Russia was the revolutionary events of 1917 and the civil war – a time of radical breakdown of all state institutions, socio-economic and spiritual-moral foundations, which became the starting point for the formation and development of a monolithic and well-organized professional Soviet underworld. The purpose of the study is to analyze the features of determination and conditions for the development of professional crime in the first years of the establishment of Soviet power. To achieve this goal, the following tasks are being solved: to study the features of the development of the domestic professional underworld in the conditions of political instability of the 1917–1920s; determine the essence of the ideological confrontation between representatives of the “tsarist” criminal world and the “new” Soviet one in the first years of the establishment of Soviet power; identify the determinants of the development of professional crime in Russia during the period under study. In the process of work, the method of synthesis, analysis, generalization, and comparative legal method are used. It is proven that against the backdrop of pronounced political instability of the 1917–1920s, which led to a crisis of traditional legal consciousness, erosion of spiritual, moral and religious values, deterioration of the socio-economic situation of the majority of the population, there was a sharp aggravation of the crime situation and, as a result, especially the active development of professional crime, which during the period under study created a real threat not only to society, but also to the national security of the state.