Neurological and EEG findings were studied in 113 children diagnosed as adjustment reaction, behavior disorder, and minimal brain dysfunction (MBD). The MBD patients were subdivided into MBD behavior and MBD learning groups, thus yielding four patient groups in all. The presence of soft neurological signs and abnormal EEG examinations increased in stepwise fashion from the adjustment reaction group to the behavior disorder group, to the MBD behavior group, to the MBD learning group. The EEG records were rated on 16 variables, including amounts and frequencies of a variety of normal EEG features as well as abnormal features. The EEG ratings were then subject to a discriminant analysis. Three discriminant functions were found to be necessary to describe the relation of the four groups. The functions were identified as cortical maturity, cortical abnormality, and cortical reactivity. This implies that the groups do not just differ along one dimension, but along three dimensions. The discriminant program correctly classified 53% of the patients.