BACKGROUND The consumption of non-ready-to-eat cereal and ready-to-eat cereal (RTEC) breakfasts have been associated with increased nutrient intakes and lower body mass index (BMI). These relationships have not been examined in low-income minority children. OBJECTIVES To evaluate, in low-income minority children, whether there is a relationship among the frequency of RTEC consumption and nutrient intakes measured at baseline, and whether there is a relationship between the frequency of RTEC and BMI controlling for age, sex, ethnicity, and energy intake. DESIGN A longitudinal study design where a cohort was followed for 3 years. SUBJECTS/SETTING Participants were 625 fourth- through sixth-grade, low-income children living in San Antonio, Texas, and enrolled in the control arm of the Bienestar Diabetes Prevention Program's cluster randomized trial. Three multiple-pass 24-hour dietary recalls were collected at the beginning of their fourth-grade year and at the end of their fifth- and sixth-grade years. Children's age, sex, ethnicity, and height and weight (used to calculate BMI) were collected between August 2001 and May 2004. STATISTICAL ANALYSES PERFORMED Descriptive and inferential statistical analyses were performed. The frequency of breakfast consumption was examined using a 6×4 cross-tabulation table with χ(2) test to establish categorical differences. The degree of association between BMI percentile and frequency of RTEC consumption adjusted for age, sex, ethnicity, and nutrition-related parameters were calculated using a partial correlation multivariate linear model analysis. RESULTS There was a significant positive relationship between the frequency of RTEC consumption and nutrient intakes measured at baseline. There was also a significant inverse relationship between frequency of RTEC consumption and BMI percentile over the cumulative 3-year period controlling for age, sex, ethnicity, and energy intake. CONCLUSIONS Children who frequently consumed RTEC had greater intakes of essential nutrients at baseline and significantly lower BMI over a 3-year period.