The theory of magnetoencephalography (MEG) and its application to epilepsy research are reviewed briefly. The MEG prediction appears to agree in general with regions where epileptiform discharges are found on the electrocorticogram. MEG appears to have a somewhat better localizing capability than EEG, although MEG may well miss the tangential component of magnetic fields. Thus, the combination of MEG and EEG may be more fruitful than either one alone.