This article analyses the relationship between the doctrine of socialist realism and Scandinavian (Danish and Swedish) working-class literature. It focuses on three authors who were part of the Scandinavian delegation at the First Congress of the Soviet Writers’ Union in Moscow – the Swedes Moa Martinson (1890–1964) and Harry Martinson (1904–78), and the Dane Martin Andersen Nexø (1869–1954) – and also on a number of influential working-class writers and critics who contributed to the discussions of socialist realism in Scandinavia: the Swedes Ivar Lo-Johansson (1901–90) and Erik Blomberg (1894–1965), and the Danes Julius Bomholt (1896–1969), Harald Herdal (1900–79) and Hans Kirk (1898–1962). Even if the direct impact of socialist realism in Scandinavia was limited, it still received attention in literary debates. This article argues that the analysis of the relationship between socialist realism and Scandinavian working-class literature can generate new insights not only about two specific left literary cultures, but also regarding the conceptualization of such cultures in an international context. The nature of the relation and the exchange between the doctrine of socialist realism and Scandinavian working-class literature in the late 1930s, the article argues, emphasizes the heterogeneity of the cultural geography of socialist world literature due to its multifaceted manifestations in different national and regional contexts. Thus, the study of this literature must stress the existence of many, different and even potentially conflicting left literatures.