This article draws attention to the practices of non-adjudicative activities by the International Court of Justice (ICJ) and conducts a case study on its presidential speeches before the United Nations. Inspired by organizational ecology theories, I consider that the international judicial system is equivalent to ecology, where international courts exist as rational actors. Within the ecology, each court is driven by self-interest, and its behaviours are thus designed to obtain a better position in this system. By conducting a thematic analysis, I found three patterns in the speech transcripts: frequent reference to other international courts, intention to enhance the Court’s identity, and advertising for the Court’s capacity to entertain environmental disputes. I argue that the patterns in ICJ presidential speeches represent evidence of an inter-court competition. This argument has important implications for research on international courts as well as for studies on inter-organizational relationships among other types of international organizations.