This paper looks at the course of Greek-Yugoslav relations from the Paris Peace Conference to the Treaty of Lausanne. Following the end of the First World War Greece and the newly-created Kingdom of Serbs, Croats and Slovenes formed a common front on an anti-Bulgarian basis, putting aside unresolved bilateral issues. Belgrade remained neutral during the Greek-Turkish war despite the return of King Constantine. But after the Greek catastrophe in Asia Minor the relations between Athens and Belgrade were lopsided.