Five children with epilepsy with "continuous spike-waves during slow sleep" (CSWS) are reported. The main clinical features of CSWS include (a) onset between 5 and 7 years of age, (b) the occurrence of several types of seizure (i.e., partial motor, generalized motor, and atypical absence), and (c) the presence of language disturbances and abnormal behavior based on emotional impairment. The EEG findings were characterized by sleep tracings showing almost continuous (greater than 95%), diffuse slow spike and wave activity. After treatment with valproate (VPA) (or ethosuximide, ESM) and clonazepam (CZP), the spike and wave complex status disappeared. Symptoms and signs of the CSWS also decreased. We suggest that combined treatment is an appropriate treatment for CSWS.