Thirty-four children were assessed for body composition, blood pressure, lipids, glucose tolerance, markers of insulin resistance, oxidative stress, and adipokines. Children were divided into 3 groups: (1) normal weight, (2) overweight but otherwise healthy, and (3) overweight with the metabolic syndrome. There were no differences among any of the groups for age or Tanner stage, and anthropometric variables were similar between the overweight and the overweight with the metabolic syndrome groups. Differences across groups were found for high-density lipoprotein cholesterol (P<.001), triglycerides (P<.01), fasting insulin (P<.001), homeostasis model assessment (P<.01), adiponectin (P<.05), leptin (P<.0001), C-reactive protein (P<.0001), interleukin 6 (P<.0001), and 8-isoprostane (P<.001). In children, oxidative stress and adipokine levels worsen throughout the continuum of obesity and especially in the presence of components of the metabolic syndrome. Overweight children with components of the metabolic syndrome may be at elevated risk for future cardiovascular disease.