Chronic obstructive bronchitis with inadequate response to inhaled steroid and bronchodilator therapy is a rather rare disorder in children. Persistence of an adenoviral infection has been described as a possible cause of unremitting airway obstruction. We studied a group of 11 children with the clinical feature of chronic bronchial obstruction. A high‐resolution computed tomography (HR‐CT) scan was performed and typically showed hyperinflation and ground‐glass‐like opacities. All children underwent either bronchoscopic transbronchial or open lung biopsy. Biopsy specimens were stained with monoclonal antibodies detecting adenoviral antigen and analyzed by light‐microscopy. Bronchoalveolar lavage (BAL) fluid was cultured for adenovirus, and antigen detection tests were performed. While some children had a history of proven adenoviral infection at the onset of their disease, in none of the cases could a persistence of adenovirus be shown. We conclude that adenoviral infection might act as a starter of chronic obstructive bronchitis in children, but that pathogenetic mechanisms other than persistent infection must be responsible for the chronicity of the disease. Pediatr Pulmonol. 2001; 32:367–371. © 2001 Wiley‐Liss, Inc.