Abstract: Non-Governmental Organizations (NGOs), as spontaneous and independent entities from the state, operate with the aim of addressing social issues and providing services to the general public. This article, posing the main question of “What are the mechanisms of NGOs’ criminal intervention in the protection of public rights?”, employs a descriptive-analytical method and utilizes library-based resources to explain the various modes of NGO involvement in criminal proceedings and their impact on safeguarding public rights. It further analyzes the legal challenges and capacities of such participation within Iran’s criminal justice system compared to those of France, the United Kingdom, Canada, and Australia. The research findings indicate that NGOs in Iran’s legal system can act as informants by leveraging legal frameworks such as the Directive on the Supervision and Pursuit of Public Rights, the Draft Bill on the Protection of Public Rights, and the Judiciary's Transformation and Excellence Document. However, even this utilization cannot compensate for the limitations imposed by Article 66 of the Iranian Code of Criminal Procedure, which restricts NGOs’ participation to reporting crimes and attending trial proceedings, without granting them the rights to file complaints, submit evidence, or appeal judicial decisions. The experiences of the studied countries demonstrate that the rights to lodge complaints, present evidence, participate in hearings, advocate for the complaint’s subject matter, and appeal decisions are recognized, although the scope of NGOs’ criminal interventions in those countries is narrower than in Iran. Recognizing NGOs as active participants in the criminal process—empowered to file complaints, attend hearings, defend public rights, submit evidence, and appeal judicial rulings—represents a progressive and innovative step toward crime detection and the examination of offenses committed against public interests.