As childhood obesity has reached epidemic proportions, it is critical to devise interventions that target the root causes of obesity and its risk factors. The two main components of childhood obesity are physical inactivity and improper nutrition, and it is becoming increasingly evident that the built environment can determine the level of exposure to these risk factors. Through a multidisciplinary literature review, we investigated the association between various built environment attributes and childhood obesity. We found that neighborhood features such as walkability/bikeability, mixed land use, accessible destinations, and transit increase resident physical activity; also that access to high-caloric foods and convenience stores increases risk of overweight and obesity, whereas the presence of neighborhood supermarkets and farmers' markets is associated with lower childhood body mass index and overweight status. It is evident that a child's built environment impacts his access to nutritious foods and physical activity. In order for children, as well as adults, to prevent onset of overweight or obesity, they need safe places to be active and local markets that offer affordable, healthy food options. Interventions that are designed to provide safe, walkable neighborhoods with access to necessary destinations will be effective in combating the epidemic of obesity. © 2011 Mount Sinai School of Medicine.