The International Tribunal for the Law of the Sea, a judicial institution created by the 1982 United Nations Convention on the Law of the Sea, began its activities on 1 October 1996. Together with the Statute of the Tribunal (Annex VI to the Convention), the Rules of the Tribunal, adopted on 28 October 1997, govern the functioning of the Tribunal and the proceedings before it. The objective of this Commentary is to give to legal practitioners and academics a detailed analysis of the provisions contained in the Rules. In doing so, the contributors, who are Judges of the Tribunal or members of its Registry, paid particular attention to the practice and the jurisprudence of the Tribunal as well as to the corresponding provisions in the Rules of the International Court of Justice.