The study is based on follow-up data of 108 patients treated for brain abscess (mean follow-up period 11 years). The overall incidence of epilepsy was 34% (37% in supratentorial lesions). The author compared the incidence of several parameters between two groups of patients: those presenting, and those not presenting with epilepsy after brain abscess treatment. Parameters characterized by significantly different incidence in each group were taken into account as possible risk factors influencing the development of epilepsy. Sex, age of the patient, localisation and size of the abscess are discussed as presumptive risk factors modifying prediction to epilepsy. The author presents a new concept of epileptic focus formation to explain satisfactorily the results of the study on the basis of pathological mechanisms. A protocol, which may be useful to evaluate the prediction to epilepsy after brain abscess treatment is proposed.