Respiratory disorders like Chronic obstructive pulmonary disease (COPD), Bronchial asthma, Interstitial lung diseases (ILD), Post infective fibrosis etc. have been known to be associated with nocturnal hypoxemia, poor sleep quality and disrupted sleep. The sleep related physiological disturbances may be associated with abnormal ventilatory control and upper airway instability during sleep. The study was a prospective study  conducted in the department of Pulmonary Medicine, at a tertiary care hospital. Before proceeding for the study, the proforma and plan of the study were submitted to the Institutional Ethics committee for Research on Human Subjects and approval was obtained. 2 among 23 patients with low risk, 1 among 9 patients with intermediate risk, 12 among 18 patients with high risk on SACS had OSA. Based on the Sleep Apnea Clinical Score (SACS), 23 patients were found to have low risk of OSAS, 9 patients intermediate risk and 18 patients high risk of OSA.