China is undergoing a rapid transition from a rural to an urban society. This societal change is a consequence of a national drive toward economic prosperity. Rapid urbanization impacts on infrastructure, environmental health and human wellbeing. Unlike many cases of urban expansion, Chinese urbanization has led to containment, rather than to increase, in the spread of infectious diseases. Conversely, the incidence of chronic conditions such as cardiovascular and metabolic diseases has risen, with higher rates occurring in urban regions. This rural–urban gradient in disease incidence seems not to be a reflection simply of more aggressive diagnosis or healthcare access. Other diseases exhibit little rural versus urban differences (e.g., liver cancer or respiratory disease), or even occur at a higher rate in the rural population (e.g., esophageal cancer). This article examines the impact of this changing demographic on environmental health and human wellbeing in China. Lessons learned from epidemiological studies mostly carried out in Europe and the U.S. may not be directly transferable to China. We advocate that there is now a need to establish robust systems of accurate data collection, a Chinese biobank network to facilitate the profiling of human health effects, and relevant randomized controlled trials to identify effective interventions in the Chinese urbanized setting. Such studies could allow for the future implementation of disease-preventive strategies.