Ten patients, aged 7 to 16 years, were prospectively evaluated for chronic cough of more than 4 months duration. All patients denied wheezing, but in addition to cough complained of chronic obstructive nasal symptoms. Sinus roentgenograms were consistent with sinusitis in 7/10 patients. Methacholine bronchial provocation was positive in 6/9 patients. The patients were recalled for a 2-year follow-up evaluation. Of seven follow-up patients, bronchial asthma had developed in three, two patients had chronic cough and exercise-induced bronchospasm, and two patients had chronic cough without wheezing. Methacholine bronchial provocation was positive in 6/6 patients. Sinus roentgenograms were compatible with sinusitis in 4/7 patients. Chronic cough in some children may be a complaint of diffuse hyperreactive airways complicated by sinusitis. In some of the children the clinical course evolved into a diffuse respiratory tract disorder including chronic obstructive eosinophilic rhinitis, recurrent or chronic sinusitis and bronchial asthma. An IgE-mediated mechanism usually could not be shown in the pathogenesis.