Infants in the neonatal intensive care unit (NICU) may be lost due to risks such as being sensitive, frequent exposure to birth complications and being prone to infection. The most common causes of mortality in newborn babies in the world; Complications due to preterm delivery (28%), infections (26%) and perinatal asphyxia (23%) were reported. Respiratory problems are observed in 4-6% of newborns. These problems are also important causes of mortality in the neonatal period. Newborn infants are more likely to have respiratory distress due to difficulties in airway calibration, few collateral airways, flexible chest wall, poor airway stability, and low functional residual capacity.Invasive mechanical ventilation (IMV) is frequently used in the treatment of newborns with respiratory failure. Various ventilation modes and strategies are used to optimize mechanical ventilation and prevent ventilator-induced lung injury. Among the important issues to be considered in newborns connected to mechanical ventilator (MV); Choosing an appropriately sized endotracheal tube to reduce airway resistance and minimize respiratory workload, correct positioning, regular nursing care, chest physiotherapy, sedation-analgesia, and infection prevention are also included.The preference for using non-invasive mechanical ventilation (NIMV) modes in NICUs is also increasing. Despite this, the use of IMV is still often required in preterm infants in the need for respiratory support and in the treatment of respiratory failure. Today, extremely preterm infants are extubated quickly. Because prolonged IMV can be a very important risk factor in the development of Bronchopulmonary Dysplasia (BPD). The reason for this is the physiological characteristics of newborns such as airway maintenance and cleanliness, smaller airway calibration, reduction in collaterals, flexible chest wall, poor airway stability, and low functional residual capacity. A small amount of secretion in preterm infants can produce a large increase in airway resistance. This reduces airflow and without expiratory flow, secretions cannot be expelled. With chest physiotherapy (CP), adequate expiratory flow can be achieved without causing airway closure.Chest physiotherapy techniques (CP) create mechanical effects in the lung, increasing ventilation, facilitating the removal of secretions and preventing bronchial obstruction. This ensures correct protection of the airways and facilitates extubation. Prolonged intubation and increased length of stay in NICUs can also lead to complications such as atelectasis, respiratory infections and chronic lung disease. Decreased oxygenation and excessive accumulation of secretions cause widespread increase in airway resistance, leading to prolonged ventilation or oxygen support. Oxygen therapy is an integral part that is frequently used as respiratory support in NICUs. However, long-term oxygen therapy may cause excessive accumulation of bronchial secretions. This makes CP mandatory. Traditional CP has become an indispensable part of airway management in NICU settings to remove excess bronchial secretions and thereby increase oxygenation. There are many studies on CP in the literature.In some of these studies, it was found that it did not prevent atelectasis, that CP had no effect, or that CP accelerated weaning from MV. The role of CP in reducing respiratory morbidity in infants and neonates continues to be debated and more studies are needed. CP needs to be supported by well-controlled studies with large sample sizes, particularly regarding the techniques used and specific protocols. Therefore, in this study, it is aimed to compare the acute effects of CP methods applied in different positions in preterm newborns.