This interdisciplinary research develops a frameworkor a model for the study of the politicization ofethnicity, a process that transforms peaceful ethnicconflict into violent inter-ethnic conflict. Thehypothesis investigated in this study is that theethnopolitical conflict that led to the break up offormer Yugoslavia was the result of deliberatepoliticization of ethnicity. The model consists ofthree variables—ethnic entrepreneurs as actors, andmass media and political rhetoric as their tools forpoliticization of ethnicity. Ethnic entrepreneurs,with a conscious interest in mobilizing ethnicity,are given this opportunity in transitional societiesin which politicized ethnicity has become the crucialprinciple of political legitimation. This studyseeks to explain how political leaders may turn intoethnic entrepreneurs and then draw upon existingnon-violent ethnic tensions and conflict (aphenomenon existing in every multiethnic society) togenerate ethnopolitical conflict. The propositions ofthe model will be tested through a case study ofYugoslavia, specifically, a comparative study of theYugoslav subunits Croatia and Serbia.