OBJECTIVE Aspiration of foreign body presents a high incidence of mortality during the paediatric life period. Family suspect and detection of specific symptoms and signs determine the need of bronchoscopy. The objective of this study is to establish the clinical parameters that indicate foreign body in airway. METHODS Retrospective study in 44 children with foreign body aspiration. We reviewed age, sex, family suspect, blood analysis, chest x-ray, time to consulting, location, type, complications, and time to discharge. RESULTS Decisive clinical factors that indicate foreign body in airway are family suspect and respiratory clinic. Findings after auscultation and chest x-ray support suspect, but final diagnostic only can be made after bronchoscopy. Bronchoscopy with foreign body removal was performed during first 24 hours in 86.36 % of patients, and founded that those with delayed diagnosis had increased morbidity. CONCLUSIONS Family's suspect is the most important parameter that indicates foreign body located in airway. Bronchoscopy performed during the first hours avoids morbidity. This is a secure technique when performed in adequate place with trained personnel.