This article examines the previously unexplored role of the Cannes Film Festival as an alternative arena for Cold War politics and the playing out of the West German Hallstein Doctrine in 1957 and 1959. The Hallstein Doctrine was an important strategic tool for the West German government, designed to marginalise the East German state on the world stage. With its politicians and diplomats unwelcome in most of the western world, the GDR increasingly invested in cultural ambassadors who were able to travel to countries to which East German politicians were routinely refused entry. In December 1956, the West German Foreign Office learnt of the intention of the organisers of the Cannes Film Festival to invite the East German film studio, DEFA, to participate in the Festival. The decision provoked outrage in Bonn and officials embarked on a sustained diplomatic campaign to remove East Germany from the Festival the following year. The Foreign Office's efforts were ultimately frustrated: not only did DEFA participate in the Festival but, two years later, the East German film Sterne (Konrad Wolf, 1959), went on to win the coveted Prix du Jury. This article will trace the efforts of the West German government to exclude the GDR from the Festival and examine how Sterne managed to break through notions of what constituted an ‘East German’ production in 1959.