This article argues that specific characteristics of the domestic legal institutions of Islamic law states shape these states' choices of peaceful resolution methods in territorial disputes. After providing original data on the characteristics of Islamic legal structures, I systematically compare pertinent rules of international dispute resolution methods and Islamic law. I demonstrate empirically that not all Islamic law states view international settlement venues in the same way. Secular legal features, such as constitutional mentions of education, supreme court, or peaceful settlement of disputes have the power to attract these states to the most formal international venues—arbitration and adjudication. On the other hand, Islamic law states whose legal system is infused with Islamic religious precepts are attracted to less-formalized venues.