Background Eustachian tube dysfunction is characterized by insufficient dilation, leading to secondary pathologies in the middle ear. By comparing pre- and post-operative grades of Eustachian tube functionand nasal resistance measurements, this study seeks to determine if septoplasty can improve Eustachian tube function in cases where nasal septal deviation is likely to cause mechanical dysfunction. We also aim to validate the JainBhalerao endoscopic classification of nasal septal deviation by assessing its utility in identifying septal deviations at a higher risk of causing Eustachian tube dysfunction. The ultimate goal is to establish guidelines for aural indications of septoplasty in treating Eustachian tube dysfunction-related middle ear disorders. Material and methods This prospective observational study was carried out from 1stJune 2022 to 31st March 2024 in the Department of Otorhinolaryngology at Acharya Vinoba Bhave Rural Hospital, involving 66 patients diagnosed with chronic otitis media and a deviated nasal septum with Eustachian tube dysfunction. Pre-operative and post-operative improvement in Eustachian tube function and Nasal resistance and their correlation werestudied using dynamic slow-motion video endoscopy and active anterior rhinomanometry, respectively. Statistical analysis included the chi-square test. Results Sixty-six patients diagnosed with chronic otitis media and deviated nasal septum with Eustachian tube dysfunction included in this study had a mean age of 35.6 years with 43 (65.2%) male predominance. Gross luminal narrowing and discrepancy of the volume of both nasal cavities led to higher degrees of Eustachian tube dysfunction due to pressure drop on the affected side, as observed in types 6, 7, and 8 as per Jain Bhalerao classification of deviated nasal septum. Nasal resistance measured using active anterior Rhinomanometry (Rhinodebitometry) showed a positive association of severity of nasal resistance in the types 6, 7, and 8 DNS of the Jain Bhalerao classification of deviated nasal septum. It demonstrated an improvement in the grade of Eustachian tube function and nasal resistance post-septoplasty. Conclusion The deviated nasal septum is one of the causes of Eustachian tube dysfunction and increased nasal resistance. Certain types of DNS are adversely associated with the causation of greater degrees of Eustachian tube dysfunction of mechanical type. Nasal septal deviation correction improved Eustachian dysfunction and nasal resistance after septoplasty.