One of the rare causes of chronic cough in children is foreign body aspiration. Nine years old girl presented with a history of cough persisting for the last 6 months. Although it was expressed that she had swallowed her tooth, she was prescribed drugs for pneumonia and asthma but did not have any diagnostic work-up. On physical examination there was expiratory wheezing on right hemithorax and also breath sounds were decreased on right. Laboratory was unremarkable except for mild leukocytosis. In the chest X-ray there was an opacity of peribronchiolar area. Patient was diagnosed as foreign body aspiration. Bronchoscopy was performed by department of pediatric surgery. A molar tooth was removed from right bronchus. There was not any problem in the follow-up of the patient. This case report emphasized the importance of history, physical examination and chest X-ray in evaluation of schoolchild with chronic cough once again.