A densitographic evaluation of regional lung ventilation represents a positive contribution also for the diagnosis of x-ray non-contrast foreign bodies aspiration, especially when both physical and skiagraphic findings are unconvincing. Dynamic lung densitography is a convenient undemanding method, that can be used even in the youngest children. In 5 adults and 4 children proven localized bronchial obstruction confirmed the suspicion of aspiration of non-contrast foreign body. In one patient with negative densitographic finding a following bronchoscopy excluded the presence of a foreign body in lower airways, too. Therefore no endoscopy was performed in another adult, as well as in one 19-month old child, who had no densitographic disturbance of regional ventilation. Densitographic examination of regional lung ventilation substantially attributes to early diagnosis of non-contrast foreign body aspiration. Such early diagnosis represents important prevention of the development of serious bronchopulmonary complications. Exclusion of the regional lung obstruction allows to avoid the otherwise indicated bronchoscopy, that does not represent, especially in elderly persons and youngest children, a simple and non risk examination.