Food marketing and advertising may be important determinants of childhood obesity. However, empirical attention has focused on television as a vehicle of marketing to children in the home, with limited attention to the broader nutrition environment in which families are embedded. This study will address this gap in the literature by evaluating food marketing targeted to young children in community retail food stores. Specific research questions include: (1) Are there differences in how food is marketed to young children in the retail food store environment based on neighborhood socioeconomic position? (2) Is there an association between neighborhood levels of food marketing and childhood obesity? (3) Can interventions and public health policy for food marketing in retail food stores be informed by the perceptions of family, store owners and public health decision makers in communities? This study will employ a cross-sectional mixed method approach using spatial mapping, surveys of food stores and semi-structured interviews.