International collaboration in science, technology, and innovation has attracted considerable attention in policy-making domains. This study focuses on a prominent example of such international collaboration, namely multilateral engagement within international organizations, and proposes a framework for ranking these organizations to guide decisions regarding membership and optimal utilization of their capacities. The main research question is: “Can a framework with specific criteria be designed to rank international science and technology organizations to inform decisions on participation and membership?” To address this question, the study hypothesizes the creation of a function-oriented framework for international science and technology organizations. These functions include: facilitating and supporting interactions, communications, and networking among individuals, organizations, and governments; providing legitimacy and enhancing the organization’s regional or international image; developing international science and technology regulations and standards; producing, processing, and disseminating information; monitoring and ensuring compliance with international regulations; allocating and sharing resources; promoting collaboration and joint initiatives; mediating and resolving international disputes; and providing education, empowerment, and capacity building. Using this proposed framework, forty-six active international science and technology organizations involved in policy-making were evaluated and categorized into six ranking tiers. Findings indicate that the Islamic Republic of Iran predominantly participates in organizations ranked between the second and fourth tiers according to the proposed framework. Finally, recommendations are provided for reviewing Iran’s membership in these organizations and for optimizing the utilization of their capacities based on the identified functions.