Objectives: Narcolepsy is a disabling disease with a delayed diagnosis. At least 3 years before the disorder identifi cation, several comorbidities can be observed in patients with narcolepsy. The early recognition of narcolepsy symptoms may improve long-term prognosis of the patients. Thus, we aimed to investigate the prevalence of the symptoms associated with narcolepsy and its social and psychological association in a sample of Sao Paulo city inhabitants. Methods: We performed a cross-sectional evaluation with 1,008 individuals from the Sao Paulo Epidemiologic Sleep Study (EPISONO). Excessive daytime sleepiness (EDS) was assessed by the Epworth Sleepiness Scale. Volunteers were also asked about the occurrence of cataplectic-like, hypnagogic or hypnopompic hallucinations, and sleep paralysis symptoms. The participants underwent a full-night polysomnography and completed questionnaires about psychological, demographic, and quality of life parameters. Results: We observed a prevalence of 39.2% of EDS, 15.0% of cataplectic-like symptom, 9.2% of hypnagogic or hypnopompic hallucinations, and 14.9% of sleep paralysis in Sao Paulo city inhabitants. A frequency of 6.9% was observed when EDS and cataplectic-like symptoms were grouped. The other associations were EDS + hallucinations (4.7%) and EDS + sleep paralysis (7.5%). Symptomatic participants were predominantly women and younger compared with patients without any narcolepsy symptom (n = 451). Narcolepsy symptomatology was also associated with a poor quality of life and symptoms of depression, anxiety, and fatigue. Conclusions: Narcolepsy-related symptoms are associated with poor quality of life and worse psychological parameters. A lthough narcolepsy may be considered a rare neurological condition, the repercussions of this disorder are substantial. Narcolepsy induces a 1.5-fold increase in the mortality rate compared with healthy individuals.1 As a consequence, narcoleptic patients have approximately 2-fold increased rates of hospital or other medical services admissions.2 Narcolepsy is often associated with a tetrad of symptoms, including, excessive daytime sleepiness (EDS), hypnagogic or hypnopompic hallucinations, sleep paralysis, and cataplexy. EDS is the most frequent symptom observed in narcoleptic patients. 3 In the natural history of EDS, several cardiometabolic and psychiatric conditions are associated with the incidence and persistence of EDS. 4 Patients with narcolepsy experience the symptoms over a long period until receiving the defi nitive diagnosis, ranging between 10 and 15 years. 5,6 A possible factor associated with this delay could be the failure to recognize the characteristic clinical features.7 Indeed, Jennum et al. demonstrated that narcoleptic patients present a wide range of comorbidities at least 3 years before the narcolepsy diagnosis, including a higher frequency of neurological diseases and other sleep disorders. 8 The recognition of the symptoms associated with narcolepsy seems to be an important approach for a better long-term progn...