The article deals with the Soviet policy towards the former tsarist concessions in Iran in 1921-27. Despite the renunciation of the former tsarist concessions in Iran, the Soviet leadership de facto tried to control the disposal of the strategically most important of them: either through legal instruments or by force. The analysis of the existing sources on the problem demonstrates that at the heart of the policy there were the strategic interests of the Soviet state. The interests were related to the security of the Soviet southern borders, primarily in the Caspian region.