characterize executive functions in drug-free patients with narcolepsycataplexy (NC) and to determine whether the executive deficits observed in patients with NC are specific to the disease itself through hypocretin deficiency or whether they reflect performance changes due to the severity of excessive daytime sleepiness. Materials and Methods: Twenty-two subjects with NC, 22 with narcolepsy without cataplexy (NwC) matched for age, gender, intellectual level, objective daytime sleepiness, and number of sleep onset REM periods (SOREMPs), and 32 healthy controls matched for sex, age, and intellectual level. Participants underwent a standardized interview, completed questionnaires (depressive symptoms and self-reported cognitive complaint), and neuropsychological tests (alertness and executive processes: updating, inhibition, and shifting). All patients and 18 controls underwent a polysomnography followed by multiple sleep latency tests (MSLT), with neuropsychological evaluation performed the same day. Results: Irrespective of diagnosis, patients reported higher cognitive complaints associated with the intensity of depressive symptoms. NC performed slower andmore variably on simple reaction time tasks than NwC, who were similar to controls. This general cognitive slowing was related to the severity of objective sleepiness in NC. NC and NwC performed slower, reacted more variably, and made more errors than controls on all executive functioning tests. Individual profile analyses pinpointed a clear heterogeneity of the severity of executive deficit related to objective sleepiness, greater number of SOREMPs, and lower intelligence quotient. The nature and severity of executive deficits were unrelated to NC and NwC diagnosis. Conclusion: We demonstrated that drug-free patients with NC and NwC presented large cognitive complaints associated with higher intensity of depressive symptoms, and altered executive functioning which may be explained by the severity of objective sleepiness and global intellectual level.