The rules of criminal procedure, to the same extent that they are used to punish the guilty, also prevent the punishment of the innocent. Therefore, criminal procedure is based on fundamental principles that guarantee the rights of the accused and safeguard public trust in the criminal justice system. Violation of these principles, especially by judicial officers, not only weakens individual rights but also affects the efficiency of the judicial process. The present study aims to analyze the sanctions for violating the principles of criminal procedure in the legal systems of Iran and Egypt, using a comparative method and drawing on library resources, domestic laws (including the constitution, Islamic Penal Code, and Code of Criminal Procedure of both countries), judicial rulings, and international documents. Findings show that in Iran, the sanction of invalidating evidence is provided for in a limited way, mainly regarding confessions resulting from torture or illegal actions by officers, while in Egypt, Article 302 of the Code of Criminal Procedure and the rulings of the country's Supreme Court invalidate any confession resulting from coercion. Despite this, weaknesses in the supervision of officers and the dispersion of regulations have reduced the effectiveness of sanctions in both countries. The research concludes by emphasizing the necessity of formulating a general rule of invalidation, integrating laws, specialized training for officers, and strengthening independent supervisory bodies