Introduction Racial/ethnic minority communities are at increasingly high risk for chronic diseases related to obesity. Access to stores that sell affordable, nutritious food is a prerequisite for adopting a healthful diet. The objective of this study was to evaluate food access, availability, and affordability in 3 nonoverlapping but similar low-income communities in urban Los Angeles, California. Methods Using a community-based participatory research approach, we trained community members to conduct a food assessment to 1) map the number and type of retail food outlets in a defined area and 2) survey a sample of stores to determine whether they sold selected healthful foods and how much those foods cost. We used descriptive statistics to summarize findings. Results Of the 1,273 food establishments mapped in the 3 neighborhoods, 1,023 met the criteria of “retail food outlet.” The most common types of retail food outlets were fast-food restaurants (30%) and convenience/liquor/corner stores (22%). Supermarkets made up less than 2% of the total. Convenience/liquor/corner stores offered fewer than half of the selected healthful foods and sold healthful foods at higher prices than did supermarkets. Conclusions Access to stores that sell affordable healthful food is a problem in urban Los Angeles communities. Healthful food strategies should focus on changing food environments to improve overall community health.