목적: Postnasal drip symptom is related to several diseases, but not every patients are clearly diagnosed. Patients with chronic, idiopathic postnasal drip symptoms are easily overlooked, and their clinical features are yet to be identified. The research was conducted to analyze clinical aspects of chronic idiopathic postnasal drip and suggest it as a distinctive entity. 방법:A single-center, retrospective cohort study was designed, involving 157 patients aged 12 years or older who visited the rhinology clinic in South Korea for chronic postnasal drip symptoms. Collected variables were general demographic characteristics, features of postnasal drip (time of occurrence, duration, time of daily occurrence, viscosity, discomfort score according to the visual analogue scale), accompanying symptoms (cough, rhinorrhea, nasal stiffness, postnasal pruritis, throat discomfort), prescribed medications, subjective response to empirical treatment by oral first- generation antihistamine-nasal decongestant(pseudoephedrine), whether and when symptoms re-occurred. Descriptive analysis and crosstab analysis between collected data were performed. 결과:Mean age of patients was 55.4±17.0 years old. Median duration of symptom was 36 months (12-66) and severity in visual analogue scale was 7(5-8). Throat discomfort was the most frequently associated symptom (73.7%). 30.3% of patients presented cough. Viscosity of postnasal drip was associated to rhinorrhea and throat discomfort. 71.6% of patients responded to 1st generation antihistamine-decongestant medication. 25.9% of patients presented symptom re-occurrence. Patients with nasal stiffness or persistent symptom presented higher re-occurrence rate compared to others. 결론:The authors report clinical features of chronic idiopathic postnasal drip patients and propose it as a distinctive term aiming to clarify diagnosis and help further research.