Thirty-two hours (night-day-night) of polygraphic recordings were performed on 14 patients with a diagnosis of narcolepsy-cataplexy. Half of the patients stayed in bed during the day, whereas the other half were seated at a table. Patients were free to nap whenever they wanted to. Patients under continuous bedrest slept 2-3 times more during the day than patients who were sitting at the table. Rapid-eye-movement (REM) sleep and slow-wave sleep (SWS, stages 3 and 4) were nearly absent during daytime sleep in the table group, but not in the bed group. The differential behavioral regimes during the day resulted in different amounts of SWS in the consecutive night sleep. Although SWS increased from the first to the second night in the table group, it decreased in the bed group. This result suggests that the presumably homeostatic regulation of SWS is intact in narcoleptic patients.