Globalization efforts, socioeconomic concerns shaping cities, the integration of innovative technologies into planning strategies, and attempts to deal with increasing populations have added a "new breath" to planning concepts. Airport cities could be defined as examples of postmodern cities in metropolitan areas in which the airport (with its related departments) is centered as a focal point and other facilities encircle the airport hub up to 30 kms outward in a mutualistic manner. Considering the crucial role of airports in the 21st-century globa lized world; travel activities such as international connections, business contacts, congresses, accommodation, and so forth should take place in a short time with easy access. Airport cities can provide all these elements without the need to go to the metropolitan city center and generate a new potential for the reconstruction and development of metropolitan areas. This study aims to investigate the basic information about airport cities with their spatial structure, components, general characteristics, environmental and economic impacts, and critical contributions to metropolitan areas through a theoretical framework. The study consists of three main stages in the framework of qualitative methods, such as data collection, comparison, and evaluation: (I) introduction and theoretical investigation of airport cities with their historical background, key concepts and characteristics, effects on the environment, and their role in sustainability; (II) inquiry into the theoretical knowledge through a case study (Stockholm-Arlanda Airport City); (Ill) and discussions on the potentials, possible impacts, and stimulating dynamics of airport cities regarding the future of metropolitan areas.