This study examined the cardiovascular fitness (CVF, Progressive Aerobic Cardiovascular Endurance Run [PACER], number of laps completed) and the prevalence of at risk of overweight (AR) and overweight (OW) among 10-15-year-olds (48% girls) from the following ethnic backgrounds: African American (n = 2,604), Asian-Pacific Islander (n = 3,888), Hispanic (n = 11,680); and White non-Hispanic (n = 16,352). Hierarchal multiple linear regression analysis, controlling for height and weight, with White non-Hispanics serving as the comparison group, revealed a limited number of significant differences among PACER performances, with no values exceeding [plus or minus]4.43 laps. Odds ratios (OR) for being classified as AR or OW were significantly greater (p less than 0.01) in African American (OR = 1.25, 1.65) and Hispanic (OR = 2.33, 2.28) boys and girls, respectively, and Asian boys (OR = 1.43). The results of this cross-sectional analysis indicated negligible differences in CVF among ethnic groups, while AR and OW were consistent with previous reports for ethnic populations. (Contains 3 tables and 2 figures.)