Abstract: This study was aimed to establish non-invasive (medical) treatment of lung collapse for children who are admitted to PICU of Tabriz Children’s Hospital. During a period of 48 months (from March 2004 to February 2008), an interventional pre-experimental study carried out on 90 children suffering from lung collapse who received non-invasive treatment; which mainly consists of postural drainage, chest physiotherapy and inhalation of aerosols (fluid as floating droplets in air) and bronchodilators. Eighty six out of 90 studied patients (94.5%) with the average age of 22 months, responded to this treatment within the average duration of 3.4 days, as collapsed area of lung reexpanded. Because of simplicity and easy availability of this method of treatment and also its efficacy and scientific base; it can substitute bronchoscopic treatment and its usage be generalized to small hospitals.