Contract interpretation in the Iranian legal system, as one of the fundamental basis of contract law, plays a vital role in understanding and correctly implementing the will of the parties. Given the complexities of legal and commercial relations, ambiguity, silence, or conflict in the provisions of contracts can lead to serious disputes. This article examines the necessity, goals, functions, and challenges of contract interpretation in Iranian civil law and, by analyzing the relevant legal articles, especially Articles 220 and 224 of the Civil Code, emphasizes the importance of interpreting contracts based on the customary meaning of words. Also, this research identifies the reasons for interpreting contracts, including ambiguity, silence, and conflict, and examines the legislator's approach to interpreting contracts and the principles of interpretation in Iranian law. The results of this study show that contract interpretation not only helps to discover the true intentions of the contracting parties, but also leads to maintaining public order and justice in contractual relations. Finally, the need to establish a clear and comprehensive framework for interpreting contracts is emphasized in order to reduce disputes and facilitate international commercial relations.