Asthma is a severe problem among inner city children, and recent evidence suggests that both allergen exposure and lifestyle can impact the disease early in childhood. This study was designed to investigate the association between physical activity and wheezing among a population of inner city children enrolling in Head Start. The parents of children aged 3–5 years responded to a questionnaire (N = 144) to determine the presence and severity of wheezing and asthma. Information was also gathered regarding home environment, food frequency, and presence of other allergic diseases. Serum was obtained to measure total IgE and specific IgE levels to common allergens. Height and weight for body mass index were recorded. Lastly, motion sensor wristwatches (Actiwatch®) were worn continuously by a subset of these children (n = 54) for 6 or 7 days. Physical activity measured with the motion sensor was decreased among children with a history of wheezing. The significant differences involved those measures of activity relating to prolonged or sustained physical activity. The correlates of asthma associated with decreased levels of physical activity included: 1) a history of wheezing in the last 12 months, 2) the diagnosis of asthma, and 3) presentation to the emergency room in the last 12 months for wheezing or asthma. In a preschool-age population, decreased physical activity was observed among children with a history of asthma or wheezing. Decreased physical activity could contribute to persistence of asthma or put children at higher risk for obesity and other chronic diseases. © 2005 Wiley-Liss, Inc.