Objective: To evaluate the health-related quality of life (HRQoL) in patients suffering from narcolepsy.Methods : Subjects included 55 narcoleptic patients diagnosed at the St.Vincent hospital, South Korea, who met the International Classification of Sleep Disorders (ICSD) criteria for narcolepsy.A standardized face to face interview was used to inquire about the disease and its burdens to the patients.HRQoL was recorded using the 36-item short-form Medical Outcomes Study (SF-36).Factors of influence on decreased HRQoL were evaluated by using correlation analyses.Results: All domains of SF-36 was explained both by BDI, ESS (inverse correlation).Physical Functioning, Role limitations due to physical health, Role limitations due to emotional problems, Emotional well being, Social functioning and Pain and General health except for Energy/fatigue were explained by PSQI (inverse correlation).Conclusions: The quality of sleep, daytime sleepiness, and depressive symptoms correlated with HRQoL.More studies are needed to confirm these results, so we will recruit normal healthy group and compare HRQoL of narcoplesy group with that of normal healthy group.