Background: Recent evidence from several countries has emerged suggesting that the increase in the prevalence of childhood obesity has slowed down substantially, or even leveled off. Also in Switzerland this trend has been observed. In 2002, 20.3% and 19.1% of boys and girls, respectively, were overweight or obese in Switzerland. In 2007, the prevalence of overweight was significantly lower, with 11.3% and 9.9% of school-aged boys and girls, respectively, being overweight or obese. Further trend analyses are necessary to confirm that the stabilizing trend observed reflects a long-term change in the rates of childhood overweight and obesity.