In a prospectively studied group of 43 children with centro-temporal spikes on the EEG, only 26 had the classical epileptic syndrome related to this EEG abnormality. Ten patients never had epileptic manifestations. In the other seven cases two types of epileptiform activity were encountered: in addition to the centro-temporal spikes generalized spike-and-wave complexes or--in other patients--occipital epileptiform phenomena occurred. In these cases the clinical signs and symptoms correlated best with the non-Rolandic EEG abnormalities. Some patients had only a few centro-temporal spikes during the recording of the EEG; in others this epileptiform activity was almost continuously present. This quantitative difference had no clinical correlation. Centro-temporal spikes should probably be looked upon as an (epi)phenomenon of cerebral disfunction with a wide range of clinical and electroencephalographic expressions.