Relationship between physical activity and diet among African-American girls. Obes Res. 2004;12: 55S-63S. Objective: To examine the cross-sectional relationships between physical activity and dietary behaviors among 8-to 10-year-old African-American girls. Research Methods and Procedures: Two hundred ten 8-to 10-year-old African-American girls from four field centers participated. Computer Science and Applications (CSA) activity monitors were worn for 3 days. CSA data were expressed as mean CSA counts per minute, mean minutes of moderate to vigorous activity per day, and mean metabolic equivalents (METS) per minute. Two nonconsecutive 24-hour dietary recalls were analyzed for kilocalories; percent kilocalories from fat; daily servings of fruit, 100% fruit juice, and vegetables; sweetened beverages; and water consumption. Height and weight were measured, and information on household income, material possessions, and participant age were obtained. Results: All three expressions of physical activity were significantly negatively associated with percentage calories from fat (r ϭ Ϫ0.147 to Ϫ0.177, p Ͻ 0.01), and mean METS per minute were significantly positively associated with percentage calories from carbohydrate (r ϭ 0.149, p Ͻ 0.05) after controlling for household income, material possessions, field center, and total caloric intake. Income was inversely associated with percentage calories from fat. Discussion: Physical activity and dietary fat consumption were inversely related among African-American girls. Efforts to prevent obesity in preadolescent African-American girls should focus on increasing physical activity and lowering dietary fat consumption.