To establish whether asthma affects physical activity levels in children (aged 7–10 years) we evaluated physical activity levels in children with undiagnosed asthma (UDA), diagnosed asthma (DA), and healthy controls (HCs). A cross-sectional community-based study was performed which included a parental questionnaire on their child's respiratory health, and testing of airway reversibility and bronchial hyperresponsiveness (BHR). DA was defined as the parents' confirmation of a physician's diagnosis of asthma in the past 12 months. UDA was defined by asthma symptoms combined with airway reversibility or BHR in children without a physician's diagnosis of asthma. Physical activity was measured during 5 days with an accelerometer and a diary, and with the habitual activity estimation scale which reviews the physical activity during the past 2 weeks. The final study population comprised 1614 children of whom 81 (5%) had DA, 130 (8%) UDA, and 202 HCs. Baseline FEV1 % was lowest in children with UDA (UDA FEV1 94% predicted, DA FEV1 98% predicted, HCs FEV1 100% predicted). Using the three methods, no differences were found in the physical activity between children with UDA, DA, and HCs. Childhood asthma does not appear to be associated with a decreased level of daily physical activity in our study population. Pediatr Pulmonol. 2007; 42:1018–1023. © 2007 Wiley-Liss, Inc.