Upper airway obstruction is commonly misdiagnosed as asthma. We report on four children with recurrent respiratory symptoms who had been erroneously diagnosed as having asthma and who received anti-asthma medication for several years. The evaluation of spirometry tracing was neglected in all cases. Subglottic stenosis, tracheomalacia secondary to tracheo-esophageal fistula, double aortic arch, and vocal cord dysfunction were suspected by direct inspection of the flow-volume curves and eventually diagnosed. The value of clinical history and careful evaluation of spirometry tracing in children with persistent respiratory symptoms is critically discussed.