Applying a census tract-level definition of food deserts, areas with limited access to affordable and healthy food, ERS has identified over 6,500 food desert tracts in the U.S. based on data from the 2000 Census of the Population. In this report, we examine the socioeconomic and demographic characteristics of these tracts to see how they differ from other tracts. We describe the demographic and socioeconomic characteristics of food desert census tracts compared with all other census tracts and how these tract characteristics have changed over time. Then, using multivariate logit analysis and data from the 1990 Census and 2000 Census, we attempt to isolate which characteristics separate food desert tracts from other low-income census tracts, to help distinguish areas that are vulnerable to low access problems in the future. Descriptive results indicate that relative to all other census tracts, food desert tracts tend to have smaller populations, higher rates of abandoned or vacant homes and residents with lower levels of education, lower incomes, and lower labor force participation. Multivariate analysis indicates that census tracts with higher poverty rates are more likely to be food deserts than otherwise similar low-income census tracts in rural and in very dense urban areas. For less dense urban areas, census tracts with higher concentrations of minority populations are more likely to be food deserts, while tracts with substantial decreases in minority populations between 1990 and 2000 were less likely to be food deserts in 2000.