Although a number of studies have addressed epilepsy from a va riety of qualitative and quantitative factors, relatively little systematic or multidisciplinary work has been reported to date. The general purpose of the present study was to analyze specific kinds of data from a large series of epileptic patients to focus the significance of the findings, particularly in relation to previously published results. Correlations among the following parameters are presented: age, sex, age at onset of seizure, type of seizure, paroxysmal electroencephalogram (EEG) abnormalities, basic EEG rhythm, family predisposition to epilepsy, and the presence of exogenous factors. The basic material of the present study consists of records of approximately 7400 patients treated at the outpatient clinic of the Department of Neurology, University of Heidelberg, in whom the clinical diagnosis suggested some type of epilepsy. Initially, the first consecutive 500 patients in an alphabetically arranged file were chosen for inclusion within the study if their clinical diagnosis was supplemented by at least one EEG examination. The final study group consisted of 466 patients, since 34 patients had to be excluded because of the lack of sufficient clinical information concerning them."