The Court in session in the Great Hall of Justice, 1979

The Court

How the Court Works

The Court may entertain two types of cases: legal disputes between States submitted to it by them (contentious cases) and requests for advisory opinions on legal questions referred to it by United Nations organs and specialized agencies (advisory proceedings).

Contentious cases

Who may appear, and on what basis

Only States (States Members of the United Nations and other States which have become parties to the Statute of the Court or which have accepted its jurisdiction under certain conditions) may be parties to contentious cases. The Court is competent to entertain a dispute only if the States concerned have accepted its jurisdiction in one or more of the following ways:

  • by entering into a special agreement to submit the dispute to the Court;
  • by virtue of a jurisdictional clause — typically, when they are parties to a treaty containing a provision whereby, in the event of a dispute of a given type, one of them may refer the dispute to the Court;
  • through the reciprocal effect of declarations made by them under the Statute, whereby each has accepted the jurisdiction of the Court as compulsory in the event of a dispute with another State having made a similar declaration.

States have no permanent representatives accredited to the Court. When they are parties to a case they are represented by an agent, who plays the same role as a solicitor or avoué in a national court and is also, as it were, the head of a special diplomatic mission with powers to commit a sovereign State.

A contentious case, step by step

From institution of proceedings to judgment

The normal procedure; its course may be modified by incidental proceedings.

1
Step 1

Proceedings are instituted

  • By notification of a special agreement (Benin/Niger — an oblique stroke)
  • Or by a unilateral application against a respondent State (Nicaragua v. Colombia)
  • Receipt by the Registrar marks the opening of proceedings
2
Step 2

Written phase

  • Parties file and exchange pleadings — Memorial, Counter-Memorial, Reply, Rejoinder
  • Everything written in one official language is translated into the other
  • Pleadings stay confidential until the opening of the oral proceedings
3
Step 3

Oral phase

  • Public hearings at which agents and counsel address the Court
  • Held in the Great Hall of Justice at the Peace Palace
  • Streamed live and archived on the website
4
Step 4

Deliberation and judgment

  • The Court deliberates in camera
  • Judgment delivered at a public sitting: final, binding and without appeal
  • Any judge may append an opinion

Incidental proceedings

What can change the course of a case

Preliminary objections

Raised to challenge the competence of the Court to decide on the merits of the case — the respondent State may contend, for example, that the Court lacks jurisdiction or that the application is inadmissible. The matter is one for the Court itself to decide.

Provisional measures

Interim measures which can be requested by the applicant State if it considers that the rights that form the subject of its application are in immediate danger.

Intervention

A State may request permission to intervene in a dispute involving other States if it considers that it has an interest of a legal nature which may be affected by the decision, or may file a declaration of intervention under Article 63 of the Statute where the construction of a convention to which it is a party is in question.

Compliance with the judgment

By signing the Charter, a Member State of the United Nations undertakes to comply with the decision of the Court in any case to which it is a party. A State which considers that the other side has failed to perform its obligations under a judgment may bring the matter before the Security Council, which is empowered to recommend or decide upon measures to be taken to give effect to the judgment.

Advisory proceedings

Opinions for the organs of the United Nations

Advisory proceedings are open to United Nations organs and specialized agencies duly authorized to request them. On 21 May 2026 the Court gave its Advisory Opinion on the Right to Strike under ILO Convention No. 87, responding to the question posed by the International Labour Organization.

Advisory proceedings
Counsel addressing the Court in the Great Hall of Justice

Basic documents

The texts that govern the Court

Statute of the Court

Organization, competence and procedure of the Court, annexed to the Charter.

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Rules of Court

The detailed procedure the Court follows in contentious and advisory cases.

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Practice Directions

Directions adopted by the Court for use by States appearing before it.

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Cases

See the procedure in practice

The cases now pending before the Court, and the three currently being heard or under deliberation.

Pending cases List of all cases