Narcolepsy with cataplexy is a severely disabling disorder very often arising in childhood. Data on neuropsychological impairment in children are scant. We administered standardized neuropsychological tests to 13 children with narcolepsy with cataplexy. Overall, our patients displayed multiple patterns of cognitive and behavioral dysfunction, and often academic failure (7 cases out of 13). All children had a normal full intelligence quotient (IQ), but 3 patients presented a significantly higher and 2 a significantly lower Verbal IQ compared to Performance IQ, respectively. Mean sleep latency was significantly correlated (P < .05) to alertness functions. Eight patients displayed behavioral problems: emotional symptoms and conduct problems prevailed. Childhood narcolepsy with cataplexy represents a risk factor for subtle and heterogeneous cognitive impairments potentially resulting in academic failure, despite the normal IQ. These children also have a certain psychopathological risk. All this seems to be at least partially detached from the direct effects of daytime sleepiness.