The objective of the present work was comprehensive diagnostics of Eustachian tube dysfunction as exemplified by 82 patients with this disorder. The examination using the standard techniques was supplemented by active anterior rhinomanometry, audiometry, and tympanometry. Three-dimensional computed tomography (3D X-ray CT) was used for detailed diagnostics of the state of the nasal structures and paranasal sinuses. The study has demonstrated that 96.3% of the patients with Eustachian tube dysfunction suffer a concomitant pathology of the paranasal sinuses, nasal cavity, and nasopharynx. Difficulties of nasal breathing were experienced by 62% of the patients.