At the outbreak of the First World War, the worker sports movement in the German Empire comprised about half a million members altogether. With its diverse offering, it was an essential component of the social democratic (sub)culture, which had a strong influence in working-class circles. In the democratic societies of France and Great Britain, however, the idea of linking proletarian sport to socialist aims was anything but popular. After the First World War, in most cases, the worker sports movement, divided into a socialist and a communist camp, continued to fight a losing battle against the so-called ‘bourgeois' sports associations (which included a large number of workers), even if the leaders of worker sport associations indulged their members' wishes and adapted their sports programme to the bourgeois model of modern competitive sport. From a cross-European perspective, the present study primarily examines the influences of the socialist/social democratic and the communist movements on workers' options in the sports field. The question of the real importance of political issues and attitudes within the worker sport associations will also be addressed. Materials from inter alia the archives of Red Sport International in Moscow and from Socialist Worker Sports International (in Bonn and Amsterdam) will serve as sources.