The interwar years are relatively understudied by intellectual historians of Eastern Europe. This is especially true of the study of the region's radical left-wing cultures, where attention has tended to focus on the Marxist revisionists of the post-war decades. As a period typically identified with political repression and economic crisis, the years following the end of World War I and the outbreak of World War II are assumed to hold little interest to the intellectual historian. However, throughout Eastern Europe, the 1920s and 1930s saw the growth of rich left-wing cultures that engaged with a diverse set of ideas from Western Europe and the Soviet Union, and adapted them to their local conditions. This article explores the development of leftist ideas during the interwar period by examining three prominent figures from Yugoslavia's literary left: the Croatian modernist Miroslav Krleža, the Montenegrin critical realist Milovan Đilas, and the Slovene Christian socialist Edvard Kocbek.