This article offers an empirical test of Huntington's thesis in The Clash of Civilizations. Huntington argues that states belonging to different civilizations will have a higher propensity to be involved in international conflict. This effect should be more prominent in the post-Cold War period. The civilization factor should also interact with membership in different Cold War blocs, border contiguity, regime type, and levels of modernization, magnifying or depressing the basic effects of these variables. To test these hypotheses, a logit specification with King and Zeng's solution for rareness of events is used on the Kosimo data. The Kosimo data allow for an extension of the empirical analysis from both a temporal and a substantive point of view. This study shows that state interactions across the civilizational divide are not more conflict prone. The first eight years of the post-Cold War era also fail to give support to Huntington's thesis. Moreover, while the civilization factor modifies the effects of border contiguity and regime type, this is not sufficient to generate conditions under which differences in civilizational heritage are associated with greater risks of conflict.