This article examines the impact of anti-Russian sanctions introduced by the U.S., including the sanctions package signed on 10 August 2017, on the foreign investment activity of Russian oil and gas transnational corporations (TNCs) such as Lukoil and Rosneft in particular. The authors examine the American sanctions against Russia and identify the possible consequences of such restrictions for the development of the Russian oil and gas sector and foreign capital expansion of Russian oil and gas majors; the authors also analyze the foreign investment activity of Lukoil and Rosneft under the sanctions regime.