Pulmonary function tests are  widely used diagnostic procedures in pulmonary diseases. The results are very useful in clinical practice, although they require  proper methodology and careful interpretation in children. It is recommended to perform lung function test in laboratories qualified in working with children. The most commonly used test is spirometry. Majority of patients above 5 years is able to produce satisfactory spirometry result, although frequently it is not obtained at first attempt.

In 2005 ATS/ERS published standardization criteria for spirometry. It is recommended to use them in spirometry interpretation in adults and older children but they are not essential in younger children below 10 years. Bronchial provocation test are used for assessment of airway inflammation, through evaluation of bronchial hyperresponsiveness. Mostly they base on spirometry, especially on FEV1. In this paper recent data concerning collecting and interpreting spirometry and bronchial challenge tests especially in children are presented.