In 1947 the Board of Control published its report on the results of 1,000 leucotomies, citing therein a mortality of 6 per cent. Five years later Dr. W. S. Maclay, in his Presidential Address to the Section of Psychiatry of the Royal Society of Medicine, referred to 180 deaths during the interval, a mortality of approximately 2 per cent. Although this is a striking improvement there is still cause for apprehension, for by far the greatest proportion of fatalities arise out of haemorrhage. The second causative factor in fatal issues is infection. Something must be done to put psycho-surgery on a yet safer basis.