Introduction Although cystic fibrosis (CF) has a wide spectrum of manifestations, the respiratory disease has the most important role on the prognosis of the disease; therefore early diagnosis of pulmonary complications is essential. The presentation aim is to review the current methods available for assessing the lung function in children and their role in monitoring the lung disease.

Methods The data will be presented regarding the evaluation of pulmonary status, by age group, with reliable current recommendations, diagnostic protocols, indications and discussions on effective methods of evaluation.

Results The methods of assessment of lung status include both functional interpretation and morphological assessment of lung. If the adult lung function is evaluated by spirometry, in children younger than 6 years methods are extremely laborious or insufficiently accurate. Methods like plethysmography, specific airway resistance, forced oscillation method or multiple breath washout generates parameters use now for the assessment of the lung function.

Conclusion Determination of basic parameters like expiratory flows, lung clearance index in order to assess the correct status of the CF childrens became a necessity, for early detection of lung disease and therapeutic intervention subsequence and for establishing the transplant timing.