The present investigation was carried out in order to check on the reliability of the findings reported in a previous publication by Hamilton and Salmon (1962). In this first experiment objective assessments were made of the effects on male chronic schizophrenic patients of three activity programmes: Industrial Workshop Therapy, Occupational Therapy and a control situation in which patients did not receive any specific activity therapy. The effects of these therapeutic approaches were assessed in terms of test scores and ratings, as well as output and earnings for those patients receiving Workshop Therapy. For patients undergoing Workshop Therapy a separate assessment was made of the effects of payment by result compared with flat-rate payment, and of co-operative work compared with working as individuals. The major findings of this study were that Industrial Workshop Therapy led to greater improvement than Occupational Therapy, that the greatest changes in behaviour occurred while patients were working individually and receiving a weekly flat-rate payment, that the behavioural changes in the Workshop group continued in the second, piecework, phase of the investigation, that piecework payments did not result in greater output than flat-rate payment, and that patients working in small teams compared with patients working as individuals, both under piecework conditions, showed greater all-round improvement on the indices used to measure it.