We report the clinical and electroencephalographic characteristics of thirteen patients with midline spikes (MS), parasagital foci (PF), or both. Numerous clinical manifestations, including generalized tonic-clonic, complex partial and partial with secondary generalization could be demonstrated. The pattern of the epileptiform manifestation is unpredictable; however, we find generalized tonic-clonic seizure the commonest type (60%). Unfortunately, this data has no statistic value. Neurologic examination was normal in the majority of the patients. Regarding age, there is a marked predominance of children (84%) with MS and/or PF. Sleep constitutes the main activation method (73%) in the search for this kind of epileptiform activity. In conclusion, although the incidence of the MS/PF is quite low (0.4%), the high epileptogenic potencial (70%) of them justifies a careful and adequate evaluation of these regions. Special attention must be paid to the normal sleep complexes, mainly in children, which sometimes can mimic true epileptiform activity.