Background: Obstructive sleep apnea (OSA) is a highly prevalent, but underdiagnosed and undertreated disorder. There is a need for simple but accurate tool for early detection of patients based on their clinical symptoms and physical findings into high- or low-risk group and give information for urgent polysomnography (PSG) and further treatment to prevent serious consequences. Epworth Sleepiness Score (ESS) and Berlin Questionnaire (BQ) are the most popular and widely acceptable instruments for identification of high-risk patients of OSA. The aim of our study was to compare these two established and well-known sleep questionnaires regarding their ability to find out the probable cases of OSA in Indian scenario. Methods: This cross-sectional study was conducted at a tertiary care center on 72 adult patients with symptoms of sleep-related breathing disorders. All patients were asked to fill both ESS and BQ questionnaires. Subsequently, all patients were subjected to level-1 PSG. For each patient, the Apnea–hypopnoea index was calculated to assess the diagnosis and severity of OSA and to further compare the ESS and BQ questionnaires for their sensitivity (SN) in OSA patients. Results: A total of 14 (19.4%) patients were diagnosed as OSA by ESS while by BQ, 32 (44.4%) patients were diagnosed as having OSA with SN of 31% and 71.11%, respectively (P = 0.00004). The positive predictive value was 82.3% and 88.8% for ESS and BQ, respectively, with a negative predictive value of 43.6% by ESS and 63.8% by BQ questionnaires. Conclusion: ESS is a less sensitive diagnostic tool for early detection of high-risk patients of OSA in general population. BQ is a valid, reliable, and more sensitive parameter to screen patients for OSA and may help in improving the quality of life in such patients with proper OSA management.