The article deals with the system of legal proceedings that existed in Ancient Russia. The main attention is paid to the Russian Truth of Yaroslav the Wise as the main source of old Russian law. Russian Truth, which arose in the early feudal state of Kievan Rus with undeveloped socio-economic, political, ideological, socio-cultural and other relations did not yet know the concept of criminal and civil law and process. At the same time, the formation of the institution of private property and social inequality in the tribal societies of the Slavs, United by the single power of the Kievan Prince, contributed to the appearance and growth of various kinds of offenses among the population. This forced the government to take certain steps to prevent them and restore the violated rights and interests of citizens, which required the legislator to fairly clearly regulate the investigation of violations and consideration of cases in the courts.