The chapter examines the contribution of the case-law of the International Court of Justice (ICJ) to the clarification and development of the international law of jurisdictional immunities. It shows how the ICJ has variously restated, elaborated, and stimulated the evolution of the international law of jurisdictional immunities, affirming in the process a traditional vision of interstate relations based on free channels of intercourse and mutual non-interference. It concludes that the Court's pronouncements have been valuable and in varied measure influential, both doctrinally and politically.