According to many analysts, there is a general affinity between Eastern Orthodoxy and nationalism, especially in Southeastern Europe. The present article aims to draw a more differentiated picture and shows that in Bulgaria, Romania and Serbia religious nationalism developed with different intensity and along different paths. Among the three countries compared, Bulgaria has the weakest tradition of Orthodox sacralization of both nation and politics. This feature is rooted in the fact that Orthodoxy in Bulgarian history has frequently functioned as a frame of transnational belonging to the «Orthodox world» or as an instrument of Greek dominance, but also in its institutional weaknesses. In Romania, the influence of the Orthodox Church in society has been traditionally stronger than in Bulgaria or Serbia — a difference which can be traced back to the lower burden of Ottoman rule and a stronger historical continuity of Orthodox learning in the Danube Principalities. Here, intense Orthodox influence in society caused the secular elites to integrate elements of Orthodoxy into the national program. The Serbian case is the most contradictory one: it reveals a heavy disparity between a modest level of church influence on everyday life with a pervasive presence of national symbolism, due to the fact of Serbia’s being at the perennial geopolitical fault line and therefore in permanent conflicts with non-Orthodox powers.