The paper presents the review of pathological changes which develop within the respiratory system in patients with structural progressive idiopathic scoliosis. The impairment of the function of the respiratory system is one of the principal impact of idiopathic scoliosis on the general health and function, as well as on the quality of life. Although the fatal outcomes of respiratory failure are usually prevented by a successful conservative treatment or by the spinal surgery, the reduction of the volume of the thorax, the restriction of the thorax, as well as decreased efficacy of the respiratory muscles are still a major issue (problem) for many patients with structural scoliosis that may lead to respiratory insufficiency or failure. The papers presents main functional tests to assess the respiratory impairment and the basic rules for interpretation of the results of the examination.