Two distinct trends can be identified in the context within which nursing care is planned and delivered. One is the continuous pressure to find ways of increasing efficiency and cost-effectiveness. The second is the widespread expectation that public services in general, and health services in particular, should be monitored and evaluated. In these circumstances, nurses and their managers need a range of evaluative tools so that changes in the organization of nursing care can be evaluated. Hackman and Oldham's 'Job Diagnostic Survey' (JDS) approach was tested in a Paediatric Unit in which aspects of primary nursing were being introduced. The paper outlines the JDS approach in the Unit in question and offers an assessment of the value of the JDS as an evaluative tool.