A study was carried out after i.v. administration of 200 mg/Kg of taurine on 37 epileptic patients in whom frequency and duration of seizures was considerable. Twenty-two subjects were given taurine for 15 consecutive days and then, once a week for a period of 6 weeks. In 5 control cases, the daily dosage wascontinued up to the 30th day; in 5 more, up to the 45th day and finally, in 5 up to the 60th day. Out of 37 patients 15 had temporal lobe epilepsy, 10 were cases of Lennox-Gastaut syndrome, 5 had generalised epilepsy, either convulsive or non-convulsive, 4 had H.H.E. syndrome and three brothers had myoclonic familial progressive epilepsy. In each group the results were similar and may be summarised as follows: I) both interictal activity and electroclinical seizures were reduced by about 30% within the first 10 days of administration; II) between the 30th and 45th day the ictal and interictal activity returned to its initial values; III) after this period, on the 60th day, values were similar to the initial ones; IV) as far as interictal activity is concerned, the same effect was found during nocturnal sleep; V) no significant changes were noticed in nocturnal sleep cycles and stages; VI) there was no apparent evidence that any phase of sleep might facilitate any improvement. Improvement was observed in about 50% of the cases (21) both physically and psychologically. The physical improvement was noticed above all in the appearence of the skin while the psychological improvement was mostly related to both attention and memory. Any pathological aspect of personality did not appear to be modified.