Background: There is a clear disparity in health in the United States such that African Americans and Hispanics are more likely to suffer from morbidity and mortality related to chronic disease than their Caucasian counterparts. Purpose: We will determine whether fourth- and fifth-grade students' measures of health-related fitness and physical activity-related self-efficacy differed when compared by ethnicity and socioeconomic status (SES). Methods: Fourth- and fifth-grade boys and girls (N = 1432) from schools in a large Midwestern metropolitan area were given the FitnessGram fitness test and the 7-item Perceived Self-efficacy to Perform Physical Activity Scale. Results: Multivariate analyses of variance (MANOVAs) identified that both genders had significant main effects for ethnicity (P < 0.001) and SES (P < 0.001) for fitness measures and physical activity related self-efficacy. Additional post hoc analysis was completed for fitness variables and self-efficacy items. Discussion: Minority students of low SES scored lower than their Caucasian, higher SES counterparts on both fitness measures and self-efficacy to perform physical activity. Translation to Health Education Practice: Though chronic disease does not manifest itself until late in life, the health behaviors that contribute to it begin in childhood and have a cumulative effect. Thus, direct intervention strategies aimed at high-risk populations are appropriate.