COPD is a significant worldwide pestilence and has as of late become the third driving reason for death in created nations. The conjunction of COPD and OSA, known as Overlap Syndrome (OS) and is known to expand the danger of foundational maladies. Patients with COPD-OSA have a high danger of death just as expanded danger of intensifications if OSA stays untreated. This work expected to evaluate the commonness of OSA in COPD patients. This imminent observational investigation was led on 100 patients with stable COPD who were gone to at chest division, outpatient facility Benha college clinics for follow up between June 2017 and June 2019. Overnight polysomnography (PSG) was made for all patients. Commonness of OSA expanded with increment COPD seriousness with absolute pervasiveness of 60% (P esteem <0.001). AHI was essentially higher in stout COPD patients (P esteem = 0.04). Huge positive connections were found among AHI and oxygen desaturation record, neck periphery and BMI in stout COPD patients. High pervasiveness of rest disarranged taking in patients with moderate to serious COPD, Obese COPD more vulnerable to create OSA and AHI expanded with increment COPD seriousness prompting more confusion and presented COPD patient to nighttime hypoxaemia which decline personal satisfaction.