centrality and access to resources beyond their adjacent hinterlands. Nowadays, for the sustainability of gigantic bodies of metropolises in developing countries and to alter their parasitic and consumptive role to a generative and developmental role, gaining trans-national functions is necessary. The mega-trend of globalization has provided some opportunities, though with accompanied threats, for these metropolises. On the basis of this research, Iranian metropolises have high geographical as well as socio-economic capabilities to attain trans-national functions, leading national development. The use of their comparative advantages needs to be augmented by competitive advantages (e.g., good governance, advanced ICT infrastructures, high quality of life and improved international relationships). In this regard, a set of guidelines to realize the trans-national role of Iranian metropolises to upgrade the country's international status has been proposed.