The United Nations predicts that by 2050 nearly three fourths of the world's population will live in urban areas, including cities. People are attracted to cities because these urban areas offer diverse opportunities, including the availability of goods and services and a higher quality of life. Cities, however, may not be sustainable with this population boom. To address sustainability, urban developers and engineers are building green structures, and businesses are creating products that are safe for the environment. Additionally, efforts are needed to place human health at the core of urban sustainability. Without human health, cities will not survive for future generations. Nursing is the discipline that can place human health in this position. Nursing's initiatives throughout history are efforts of sustainability-improving human health within the physical, economic, and social environments. Therefore, nursing must take a leadership role to ensure that human health is at the core of urban sustainability.