Objective: Prolonged treatment with low doses of inhaled corticosteroids may affect the growth rate; however, limited data are currently available for body composition parameters in children with asthma. We examined whether treatment with inhaled corticosteroids has an effect on body mass index, basal metabolic rate, percentage body fat, obesity degree, fat mass, and muscle mass in children with mild asthma. Materials and Methods: The study was performed in 45 children with mild persistent asthma being treated with inhaled corticosteroids and 45 healthy controls. Body composition parameters; body mass index, percentage body fat, obesity degree, basal metabolic rate, body fat mass, muscle mass, and waist-hip circumferences were measured. Written questionnaires including duration of television/computer viewing, frequency of fast food consumption, and weekly physical activity were completed. Results: There was no difference in body composition parameters and waist-hip circumference measurements between the groups. A positive correlation was demonstrated between the duration of inhaled corticosteroid treatment and the percentage of body fat, muscle mass, fat mass, and hip circumference. When compared with healthy controls, a significant increase in the duration of television/ computer viewing and frequency of fast food consumption and a significant decrease in weekly physical activity were observed in children with asthma. Conclusion: Body composition parameters seem not to be affected in the inhaled steroid-using children with asthma. However, as the duration of inhaled corticosteroid treatment increased, the percentage of body fat, body fat mass, and hip circumference also increased. Children with asthma should be encouraged to increase physical activity and be recommended to decrease the duration of television/ computer viewing.