ENSince its organizational beginning, Polish socialist thought made the issue of independence the key concern of its political platform, strategy and tactics. This clearly affected the attitude of Polish socialists to the so-called Eastern issue, that is the attitude to Russia as a conqueror, the issue of Lithuanian, Belorussian and Ukrainian territories and the shape of the Eastern border, etc. The paper presents the most representative approaches of Polish socialism to the Eastern issue. The paper is divided into two subsections, separated by the year 1918 when Poland regained its independence. Bearing in mind the ideological and doctrinal differences and those concerning the methods of action, which divided the representatives of socialist thought both before and after the year 1918,1 have tried to demonstrate that they were in agreement with respect to the fundamental issues (such as the existence of the Polish state). A consequence was their approach to the Eastern issue and general approval for the federalist concept in the East.