BACKGROUND As the prevalence of childhood obesity has risen in past decades, more attention has been given to how the neighborhood food environment affects children's health outcomes. PURPOSE This exploratory study examined the relationship between the presence of neighborhood food stores within a girl's neighborhood and 3-year risk of overweight/obesity and change in BMI, in girls aged 6 or 7 years at baseline. METHODS A longitudinal analysis of participants in the Cohort Study of Young Girls' Nutrition, Environment and Transitions (CYGNET) was conducted from 2005 to 2008. Neighborhood food stores were identified from a commercial database and classified according to industry codes in 2006. Generalized linear and logistic models were used to examine how availability of food stores within 0.25-mile and 1.0-mile network buffers of a girl's residence were associated with BMI z-score change and risk of overweight or obesity, adjusting for baseline BMI/weight and family sociodemographic characteristics. Data were analyzed in 2010. RESULTS Availability of convenience stores within a 0.25-mile network buffer of a girl's residence was associated with greater risk of overweight/obesity (OR=3.38, 95% CI=1.07, 10.68) and an increase in BMI z-score (β=0.13, 95% CI=0.00, 0.25). Availability of produce vendors/farmer's markets within a 1.0-mile network buffer of a girl's residence was inversely associated with overweight/obesity (OR=0.22, 95% CI=0.05, 1.06). A significant trend was observed between availability of produce vendors/farmer's markets and lower risk of overweight/obesity after 3 years. CONCLUSIONS Although food store inventories were not assessed and food store indices were not created, the availability of neighborhood food stores may affect a young girl's weight trajectory over time.