The aim of this paper is to point out the importance of peaceful settlement of disputes in relations between subjects of international law. It is one of the basic principles of the international law, of an imperative character. One of the ways of peaceful settlement of disputes is to settle disputes before the International Court of Justice in The Hague. The Republic of Croatia also participated in the proceedings before the International Court of Justice. In the introductory part, international legal disputes are defined and the methods and means used are briefly explained. In order to reach a peaceful agreement, the negotiation process between the conflicting parties is the most important. The use of one means to reach a peaceful settlement does not prevent parties from using another. All methods used to resolve disputes pacefully can be classified as diplomatic means or extra judical or judical method of settlemet. A brief description of the means of resolving international diputes is only an introduction to the main part of the work, which is the International Court of Justice and the Genocide Case between Croatia and Serbia. The Chapter on the International Court of Justice shows the historical development, jurisdiction, types of proceedings before the Court and the way of making decisions. The second part of this paper refers to the Genocide Case between Croatia and Serbia. In February 2015, the International Court of Justice issued a judgment on the mutual claims of Croatia and Serbia for genocide.