Based on various sources, the author of this article explores the process of the emergence of the institution of indeterminate sentences in Soviet legislation. Its American and European roots are revealed, reflected in the legislation of individual countries, discus sions on the issue of indeterminate sentences at international conferences and congresses. Also considered is the scientific position of prerevolutionary Russian scientists in relation to indeterminate sentences. Some of prerevolutionary scientists were in the public service, first during the Provisional Government, and then in the early Soviet period. In this regard, the author explores the specifics of the personnel of the Central Punitive Department of the People’s Commissariat of Justice in the initial period of its activity. It has been established that a number of prominent prerevolutionary criminologists could influence the content of Soviet legislation in terms of introducing elements of indeterminate sentences. In this regard, the first normative acts of the Soviet state of the criminal law and correctional labor industries (1918-1921) are analyzed. The author comes to the conclusion that during the period of the formation of the Soviet state in Russia, important prerequisites were formed for fixing the institution of indeterminate sentences in the legislation. The article may be of interest both for historians of law and for specialists in the field of criminal and penitentiary law.