Abstract Background: Chronic Obstructive Pulmonary Disease (COPD) is a major health problem characterized by chronic airflow limitation that is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. Aim of Study: This study was carried out to compare the therapeutic effect of prone position versus diaphragmatic release in patients with COPD in ICU. Patients and Methods: Sixty patients with COPD were randomly assigned into two equal groups. The methods of assessment included Acid-base analyzer. Group (A) lied in prone position, for one hour for five consecutive days while Group (B) received diaphragmatic release technique for five consecutive days. Results: The results showed that there was significant increase in PaO2 and O2Sat in second group compared to the first group. In relation to ABG results and O2Sat. The study revealed that the results obtained in second group were superior to that of first group. Conclusion: It was concluded that diaphragmatic release technique superior to prone position in treatment of COPD in ICU.