A simple and noninvasive monitoring of an anti-inflammatory effect of antiasthmatics is very important, because patients with persistens bronchial asthma mostly demand lifelong pharmacotherapy with inhaled corticosteroids (ICS). The measurement of nitrogen oxide in exhaled air (eNO) is a noninvasive test, which reflects a presence of eosinophillic inflammation in airways of patients with atopic bronchial asthma; additionally it is safe, easily performable and highly reproducible.