The diagnostic value of MLE, as theoretically expected, will be discussed first. Besides the estimation of background activity, a main topic is to proof and quantify the occurrence of paroxysmal, epilepsy characteristic EEG patterns, accompanied eventually by a 24 h sleep rating. First clinical experiences with 8-channel cassette recorders show - compared to 4-channel monitoring - the improved valuation of focal EEG signs, of their localization and their propagation characteristics during the phase of generalization. Thus, even for complex ictal patterns, the time course of occurrence as well as of duration and propagation can be registered. The facility that a quartz-locked clock is displayed for the patient on the recorder housing and its digital code is simultaneously stored on tape, essentially improves the possibility of selective analysis of epochs with infrequently occurring seizure events. It allows to correlate manifest and masked symptoms with ictal EEG changes. For some patients who have been strongly suspected but not finally proven to suffer from epileptic (or a combination of epileptic and nonepileptic) fits the anamnestic data and routine EEG findings may be significantly supplemented by means of 8-channel long-term recordings. Apart from searching for paroxysmal EEG-changes as a diagnostic screening, the new technique renders possible extensive mobile polygraphic monitoring (e.g. for 24-h- hypnograms ). The utilisation of 8-channel mobile long term recordings is shown in 5 cases of patients with epileptic seizures.