OBJECTIVE: Childhood obesity is higher among ethnic minorities. One reason may be the limited access to affordable, healthy options. The disparate prevalence of urban corner stores in low-income and high-minority communities has been well documented. There are no data, however, on what children purchase in these environments before and after school. The purpose of this study was to document the nature of children's purchases in corner stores proximal to their schools. METHODS: This was an observational study from January to June 2008. Participants were children in grades 4 through 6 from 10 urban K-8 schools with ≥50% of students eligible for free or reduced-price meals. A total of 833 intercept surveys of children's purchases were conducted outside 24 corner stores before and after school. The main outcomes were type and energy content of items purchased. RESULTS: The most frequently purchased items were energy-dense, low-nutritive foods and beverages, such as chips, candy, and sugar-sweetened beverages. Students spent $1.07 ± 0.93 on 2.1 ± 1.3 items (1.6 ± 1.1 food items and 0.5 ± 0.6 beverage items) per purchase. The total number of calories purchased per trip was 1497.7 ± 1219.3 kJ (356.6 ± 290.3 kcal). More calories came from foods than from beverages. CONCLUSIONS: Purchases made in corner stores contribute significantly to energy intake among urban school children. Obesity prevention efforts, as well as broader efforts to enhance dietary quality among children in urban settings, should include corner store environments proximal to schools.