In a preliminary report (Brit. Med. Journ., 2, 310, 1940), two modifications were introduced in Sakel's technique for the insulin treatment of schizophrenia, with the primary object of continuing the treatment under wartime conditions. The first and most important of these was concerned with the saving of sugar. This simple method, by which glucose is given intravenously and is followed by a drink of potato soup as soon as the patient is awake, has already been fully described by us. We discovered incidentally that this method effected a saving of insulin amounting to 46.6 per cent. in seven patients. Various critics have asked why other workers have not effected a saving by using intravenous insulin. Further, we have been asked what advantages are to be gained by giving insulin intravenously apart from this saving of the drug; whether intravenous insulin adds any dangers to the treatment, and whether it brings about a remission in schizophrenia comparable with intramuscular insulin. We have had more than a year's experience with the use of intravenous insulin, and this paper aims at describing our first year of this experience and answering the questions set out above. We may mention that in 24 additional patients treated, an average saving of 28.3 per cent. of insulin has been effected.