The purpose of the study was to explain childhood respiratory infections in terms of life-style factors like being overweight or physically inactive. In the course of the cohort study we gathered data on respiratory health of 1028 preadolescent children in Krakow. Recurrent acute respiratory infections (RARI) in children have been defined as frequent spells (10 or more infections) over the two-year follow-up. In scoring the physical activity level, the data on regularly exercising sport and the number of hours spent daily TV watching or doing homework have been used. Excessive weight was based on the BMI index. In the total sample, the RR estimates of RARI adjusted to BMI and other potential confounders were consistently higher in children with low physical exercise (RR = 2.96; 95% CI: 1.78-4.93) or with moderate exercise (RR = 1.87; 95% CI: 1.33-2.65). Than among the highly active group. In the subgroups of allergic and non-allergic or overweight and not-overweight children the adjusted RR estimates were consistent with those found in the total sample. We concluded that physical exercise in preadolescent children may lessen the risk of acute respiratory infections and that the low physical activity is an independent predictor of increased risk of RARI besides excessive weight and other potential risk factors.