OBJECTIVE: The objective was to assess the prevalence of overweight and obesity in children in a canton of Switzerland and the association with various characteristics of the parents and the children. RESEARCH METHODS AND PROCEDURES: A cross-sectional survey was conducted in all children of the sixth school grade of the canton of Vaud, Switzerland. Weight and height were measured, and selected lifestyle variables were assessed with a self-administered semiquantitative questionnaire. Information on children's parents was gathered through a mailed structured questionnaire. Overweight and obesity were based on the International Obesity Task Force criteria. RESULTS: Of 6873 eligible children, 5207 (76%) participated (2621 boys, 2586 girls; mean age, 12.3 years; standard deviation, 0.5 year). The prevalence of overweight (including obesity) was 15.0% (95% confidence interval, 13.7% to 16.4%) in boys and 12.4% (11.1% to 13.7%) in girls, and the prevalence of obesity was 1.8% (1.3% to 2.3%) and 1.7% (1.2% to 2.2%), respectively. In both univariate and multivariate analyses, overweight was strongly associated with high television viewing time and selected characteristics of the parents (overweight, low educational level, and foreign nationality). DISCUSSION: The prevalence of pediatric overweight and obesity was lower in this region of Switzerland than in several European countries. The correlates of overweight found in this region suggest areas for potential interventions.