According to Article 167 of the Constitution and Article 3 of the Civil Procedure Act, the judge is obliged to issue a judgment based on the law. That is, the legal basis of a judgment rendered by the court must be the law, and in cases where the law is silent, refer to authentic Islamic sources or authentic fatwas or general legal principles. In the meantime, the question is whether international instruments and treaties can also be relied upon as a basis of judgments and if the answer is yes, under what condition or conditions these international documents and treaties can be relied upon as the basis of judgments and in which category and these instruments are included in which category of cases listed in Article 167 of the Constitution and Article 3 of the Civil Procedure Act? In accordance with Article 77 of the Constitution, treaties, protocols, contracts and international agreements must be approved by the Islamic Consultative Assembly and in accordance with Article 9 of the Civil Code, the provisions of the covenants concluded between the government of Iran and other countries are tantamount to law. Therefore, the treaties that Iran has joined in compliance with the formalities of the conditions contained in the Constitution, are tantamount to domestic laws and can be relied upon like domestic laws. In this report on the critique and analysis meeting, two judgments, one on the subject of the acquisition of Iranian nationality for an Afghan national and the other on the issue of requiring the defendant to divorce his wife, have been examined, and the method in which the court relied upon international treaties has been critiqued in terms of the degree of compliance with the principles of rendering judgment and the fact that judgments must rely upon the law.