ENThe article describes Soviet-Lithuanian relations in the period between 1926 and 1929, based on reports by Soviet diplomats in Vilnius. The authorities in Moscow were preoccupied with the internal situation in Lithuania, the growing tensions between Augustinas Voldemaras and Antanas Smetona, and the complicated relations between Vilnius and Warsaw. The article analyses the nuances of the changes in Soviet-Lithuanian relations after the coup in Lithuania in December 1926. The coming to power of the leaders of the Union of Lithuanian Nationalists (Tautininkas) initially resulted in a situation of uncertainty in bilateral relations. Moscow was very concerned about Augustinas Valdemaras’ attempt to exacerbate the Polish-Soviet conflict to settle the Vilnius problem in Lithuania’s favour. The Soviets feared that Voldemaras could provoke an armed conflict with Poland and that the Soviet Union would inevitably be drawn into this battle. Keywords: Augustinas Voldemaras, Antanas Smetona, Lithuanian-Soviet relations, Polish-Lithuanian relations, Lithuanian foreign policy, USSR foreign policy. [From the publication]