Effects of paradoxical sleep deprivation upon intracranial self-stimulation behavior were studied. After stable response rates to electrical brain reward were obtained, rats were assigned to an experimental group in which they were deprived of paradoxical sleep with the pendulum technique for 72 h, to a pendulum control group and to a home-cage control group. In baseline, postdeprivation, and postrecovery sessions, rate-intensity functions for intracranial self-stimulation were determined. Partially in contrast to the literature, no change in the response rate or threshold for brain stimulation was found. The question was raised whether factors accompanying the different paradoxical sleep deprivation techniques rather than paradoxical sleep deprivation itself were responsible for these behavioral differences.