This study, in two parts, compares the immediate and more long-term outcome of two groups of schizophrenic patients admitted to hospital before and after the introduction of pharmacotherapy in the form of reserpine and the phenothiazines. There have been differences of opinion as to whether the undoubted improvement which has occurred in the prognosis of schizophrenia, at least in the short term, since the introduction of chemotherapy has been due to the use of these drugs, to changes of administrative treatment, or to both. There has been evidence from mental hospital statistics (Shepherd et al., 1961) that changes in outcome began before the introduction of the drugs and were almost certainly related to the changes of administrative treatment or institutional management which have occurred in the mental hospitals over the same period. It may well be that the use of drugs has facilitated these changes as well as having a more direct effect oh prognosis, but the relative importance of these two factors is difficult to assess from mental hospital statistics. Comparison between results obtained in different hospitals is also of limited value because of the number of uncontrolled variables. There would seem, therefore, to be an advantage in the more detailed examination and comparison of a smaller number of patients admitted to the same hospital, and the present investigation is of this type. The material consists of two groups, of 50 patients each, admitted to the Professorial Unit at the Maudsley Hospital in the years 1952/53 and 1956/57 respectively. Since the policy throughout has been to admit only non-compulsory patients for relatively short-term treatment, administrative changes in this hospital between the two periods are likely to have been minimal. The aim was to compare both immediate and long-term outcome in the two groups and to examine the effect of a number of variables on this. The short-term outcome will be considered in the first and the long-term outcome in the second paper.