There is a global trend towards electing adjudication as a method of dispute resolution due to its efficiency and a measure of uniformity. The most complex cases, however, require a specialized international court, or, at least, cooperation between international judiciary bodies. The MOX Plant Case (Ireland v United Kingdom, an arbitration case pursuant to Article 287, and Article 1 of Annex VII, of the United Nations Convention on the Law o f the Sea, and Case C-459/03 Commission v Ireland) is an example of cooperation between International Tribunal for the Law of the Sea and the Court o f Justice of the European Union. The author discusses procedural issues, with particular attention paid to the conflict of jurisdiction.