Introduction: Narcolepsy is a chronic disease characterized by sleep attacks, excessive daytime sleepiness and nocturnal sleep fragmentation. It can be associated cataplexy and other disturbance of REM sleep (sleep paralysis and hypnagogic hallucinations and hypnopompic). Case report: A 10-year old boy was referred to Pedopsychiatry because of behavioural disturbance, irritability, sleepiness and distraction, being interpreted as an “ill-mannered child.” After clinical evaluation and comprehensive laboratory studies we concluded that he presented narcolepsy with cataplexy. Discussion/conclusion: Patients with narcolepsy face several problems due to the disease which, if left untreated or ineffectively treated, cause embarrassing or distre...