Physical activity is especially important of children's everyday life with chronic disease. The aim of the study was to show whether asthma is a barrier to physical activity in our society. The correlation between the severity of the disease, body mass index, and physical activity were analyzed, and, parents' opinion whether children should participate in active sports was assessed. Physical activity of children with asthma was analyzed by questionnaires and activity-measuring armbands. 93 parents and their children were involved in the survey, while 20 children were wearing the armband. The age of children was 12.6±3.5 years (mean±SD), 69.9% were boys, 30.1% were girls. 93.4% of the respondents participated in physical education program and 56.5% also attended sporting activities on a regular basis. 61.2% of the children had mild, 37.6% moderate, and 1.2% severe asthma. 6.5% of the respondents stated that their illness had been consistently or frequently limiting the performance concerning their school or home duties over the past 4 weeks. Twelve percent of parents felt that physical activity was not appropriate in the context of this disease. We conclude, that fear of the consequences of physical activity depends largely on education which should involve their parents, teachers and coaches.