THERE are only scanty reports in the literature dealing with sleep electroencephalogram (EEG) records in petit mal epilepsy. This can be easily understood since waking records are so frequently diagnostic or highly informative in this condition. It has been, however, pointed out by Gibbs and Gibbs1 that, in petit mal epileptics, seizure discharges do occur more frequently in sleep (89% of their cases) than in the waking state (84%). The Gibbses felt that the petit mal discharge is usually altered in sleep and may be replaced by a "grand mal component." Passouant et al2 investigated the reactivity to auditory stimuli during the sleep of petit mal epileptics. A more recent study from the Montpellier School by Delange et al3 dealt with nocturnal sleep in six patients with petit mal epilepsy; these authors showed suppression of paroxysmal bursts during the stage of generalized desynchronization in "paradoxical sleep."