The effects of interventions within a high-care psychiatric ward, based upon the principles of a therapeutic community, were evaluated. Interventions included an enhanced physical environment, improved communication, clear rules and aims, and improved safety procedures. A Ward Atmosphere Scale, an Attitude Scale, and interviews with staff indicated improvements in ward atmosphere and staff attitudes. Ward records showed a substantial reduction in the use of seclusion for aggressive patient behaviour, and a 62% reduction over 2 years in short-term staff illness. The authors conclude that similar interventions could be used to improve the functioning of other psychiatric wards.