Abstract: This social-cultural history explores the changing context, culture, and identity of psychiatric nurses working in New Zealand public mental hospitals between 1939 and 1972. Primary documentary sources and oral history interviews provided the data for analysis. The thesis is divided into two periods: 1939 to 1959 when asylum-type conditions shaped the culture of the institutional workforce, and 1960 to 1972 when mental health reform and nursing professionalisation challenged the isolation and distinct identity of mental hospital nurses. Between 1939 and 1959 the introduction of somatic treatments did not substantially change nursing practice in mental hospitals. Overcrowding, understaffing and poor resources necessitated the continuance of custodial care. The asylum-type institutions were dependent on a male attendant workforce to ensure the safety of disturbed male patients, and the maintenance of hospital farms, gardens, and buildings. Although female nurses provided all the care and domestic work on the female side, the belief that psychiatric nursing was physically demanding, potentially dangerous, and morally questionable, characterised the work as generally unsuitable for women. Introduction of psychiatric nursing registration which was a move toward professionalisation did little to change the dominance of a male, working-class culture. From 1960 to 1972 psychiatric nurses' identity was contested. New therapeutic roles created the possibility of the nurses becoming health professionals. Their economic security and occupational power, however, was tied to an identity as unionised, male workers. As psychiatric nurses were drawn closer to the female-dominated nursing profession through health service changes and nursing education reform, both men and women acted to protect both their working conditions and their patients' welfare. To achieve these ends, they employed working-class means of industrial action. By accepting the notion that psychiatric nurses' identity was socially constructed, this thesis provides an interpretation that goes beyond the assumption that nursing is a woman's profession. Instead, it presents psychiatric nursing as a changing phenomenon shaped by contested discourses of gender, class and professionalisation. Nursing in public mental hospitals attracted ordinary men and uncommon women whose collective identity was forged from the experience of working in a stigmatised role.