Compensation is one of the most important effects of breach of contract and one of the fundamental pillars of contractual liability, which in contemporary law is not limited to the payment of compensation by the breaching party, but the behavior of the injured party also plays an effective role in determining the limits of liability and the amount of compensable damage. The present study aims to explain the position of the injured party's participation in compensation and its comparative study in Iranian law and international documents. This study, using a descriptive-analytical method and using library resources, while studying theoretical foundations, has analyzed the provisions of domestic law and international documents, including the Convention on the International Sale of Goods, the UNIDROIT Principles of International Commercial Contracts, and the Principles of European Contract Law. The findings of the study show that international documents have accepted the participation of the injured party with a coherent approach based on criteria such as good faith, common behavior, expediency, and prevention of avoidable damages as one of the pillars of the compensation system. In contrast, although Iranian law does not have an independent regulation in this field, jurisprudential rules, general legal principles, and some legal regulations have provided the capacity to accept this institution. The results of the study also indicate that the participation of the injured party is essentially different from the institution of joint fault and governs his behavior after the breach of contract occurs. In sum, recognizing this institution within the framework of Iranian law, while strengthening contractual justice, can lead to the reduction of avoidable damages, increasing the efficiency of the compensation system, and further convergence of domestic law with international trade law standards.