Patulous eustachian tube (PET) is often misdiagnosed due to the difficulties to perform the tests designed to evaluate the function of the eustachian tube (ET). We describe a simple but very efficient test that can be performed in the clinic or by the patient himself at home to diagnose this problem by nose irrigation of physiological serum. Key points: Patulous eustachian tube, autophonia, deafness, tinnitus, physiological serum, diagnosis. Key Points: Question: Patulous eustachian tube sometimes doesn´t relieves lying in a lordotic position. Additional problems: Ussualy the problem is intermittent and diagnostic criteria include oclusion of the eustachian tube. Test design: We designed a test to occlude the eustachian tube by the patient himself at home with physiological serum. Findings: The occlusion with serum is effective in almost all the patients. Meaning: Occlusion with physiological serum is useful in the diagnosis and treatment of patulous eustachian tube.