In the present study, the natural course of patulous eustachian tube syndrome (PETS) was examined. Fifteen patients (3 males, 12 females, 21 to 79 years old; mean age, 61.1 years) were given the diagnosis of PETS, meeting the criteria of both aural symptoms and hyperpatent eustachian tube findings by sonotubometry and tubo-tympano-aerodynamic graphy. Their aural symptoms were assessed by questionnaire at a mean of 16.7 months after the initial diagnosis in the absence of continuous medical treatment. Based on their answers, 7 patients were subjectively cured or in remission, but the other 8 patients showed intractable aural symptoms. The function of the eustachian tube was then re-examined in 7 of the 15 patients after the questionnaire. Six patients with intractable aural symptoms still showed open tubal function, while the tubal function was improved in another patient with relief from aural symptoms.