Abstract The nocturnal sleep and daytime sleep tendency were assessed in 10 narcoleptics who regularly smoked cigarettes and 10 narcoleptics who did not use tobacco. Standard sleep-wake polygraphic measures were recorded during the 24-h study. There were no statistical differences between groups in terms of nighttime sleep structure, although tobacco use resulted in a decreased sleep duration. Smokers tended to fall asleep more rapidly than non-smokers throughout daytime multiple sleep latency testing. The data failed to demonstrate a daytime arousal effect of tobacco for patients with narcolepsy.