The concept of the "food desert", an area with limited access to retail food stores, has increasingly been used within social scientific and public health research to explore the dimensions of spatial inequality and community well-being. While research has demonstrated that food deserts are frequently characterized by higher levels of poverty and food insecurity, there has been relatively little research examining the relationship between food deserts and obesity, particularly in rural areas. In this article we use Geographic Information System (GIS) techniques to identify food desert areas in rural Pennsylvania. We then analyze student body mass index (BMI) data along with census and school district-level data to determine the extent to which the percentage of a school district's population residing within a food desert is positively associated with increased incidence of child overweight among students within the district. We find that school districts with higher percentages of populations located within food deserts are more likely to be structurally and economically disadvantaged. Net of these district-level structural and economic characteristics, we additionally find a positive relationship between increased rates of child overweight and the percentage of the district population residing in a food desert. (Contains 3 footnotes, 6 tables and 1 figure.)