Background. The effect of overweight on metabolic risk factors and the role of physical activity (PA) in pre-pubertal children is unclear. Objective. To study differences in metabolic risk factors between groups of normal weight and overweight children and how these risk factors are associated with objectively measured PA and cardio-respiratory fitness (CRF). Design. A cross-sectional study was conducted with 68 children aged 8-11 years. Children were categorized into normal weight (n = 39) and overweight/obese (n = 24/5). PA and CRF were measured objectively. An oral glucose tolerance test (OGTT) was performed and triglycerides (TG) and HDL-cholesterol (HDL-C) were measured. A metabolic risk score (MRS) was calculated from the standardized values of insulin, glucose, TG, inverted HDL-C and blood pressure. Results. There was a significant (P < 0.05) difference between normal weight and overweight children in clustered metabolic risk, insulin (AUC), fasting insulin and systolic blood pressure. PA and CRF did not differ significantly between groups. In linear regression analysis combining the two groups, PA was negatively associated with insulin (AUC) (beta = -0.25, 95% CI = -0.50, -0.002) and CRF was negatively associated with fasting insulin (beta = -0.41, 95% CI = -0.67, -0.15). Conclusions. Metabolic risk factors are elevated in overweight pre-pubertal children compared with normal weight controls. This is not explained by lower PA or CRF in the overweight group although PA and CRF were associated with lower insulin levels in pooled analyses. This highlights the importance of preventing overweight in children from an early age in order to prevent the metabolic syndrome and its associated diseases.