This paper examines why some ethnic minorities in Europe have successful ethnic parties while others pursue their political interests through mainstream parties. To study differential success of ethnic minorities in establishing successful ethnic parties, I adapt threats-vs-resources approach, comparing relative importance of ethnic threats (acting as motivator for collective political activism) and ethnic resources (providing different opportunities facilitating ethnic mobilization). Empirically, I focus on the post-Cold War period, including ethnic minorities in Western and Eastern Europe. I find that both ethnic threats and ethnic resources matter for success of ethnic parties. I show that increased salience of issues tied to ethnicity, either through promotion of majority ethnonationalism, or through advancement of minority ethnic rights, can foster successful ethnic parties. I also show that the logic behind successful minority political mobilization differs between Western and Eastern Europe.