Since the appearance of steam engines in the late 18th century, cities have been growing with the development of transportation and the consequent increase of its urban population and economic activities. Presently, cities accommodate more than half of the world population and are expected to be responsible for 73% of the world’s energy use in 2030. Cities come to the fore as a problem, being also the roots of solution for current environment and energy-related problems. The Transit-Oriented Development (TOD) and Bus Rapid Transit (BRT) systems applied in Latin American cities have shown the possibility of establishing efficient urban transport networks and sustainable urban structures at low cost. Meanwhile, Asian cities are anticipated to accommodate 54% of the world urban population by 2050. Sejong city, South Korea is the newest planned city in the region aiming to see its completion in 2030. The aim of this paper is to assess the future urban sustainability of Sejong city by analyzing first the Master Plan of the construction of the city in accordance with PEBOSCA (Physical, Economical, Biological, Organizational, Social, Cultural, and Aesthetical) resources, and second its implementation in general with a focus on the expected role of Transit-Oriented Development in particular looking at BRT. Putrajaya’s case is referred for anticipated shortcomings which Sejong should be prepared for. Secondary data and interpretations from books and articles regarding contemporary urban problems are comprehensively reviewed to systemically analyze the influences of implementation of TOD upon urban sustainability. This study revealed that planned actions derived from TOD will play an important role in resolving urban problems in Sejong city by relieving urban traffic congestion, CO2 emission and fossil fuel consumption. And systemic influences on improvement of business activities, government tax income, social activities and equity, and olfactory quality of the city are expected. Therefore, TOD is deemed to be a better option for existing cities and is necessary for newly developing planned cities in Asia and Africa.