This paper highlights a key area of analysis emerging from research undertaken in order to explore cultural differences between medicine and nursing, and implications for primary care. Concerns about the role of nursing in primary health care within the UK are of particular interest to the authors. A specific concern centres on the movement of health care work from one group of health workers to another, in particular from doctors to nurses. A number of studies show that work is moving from doctors to nurses and explore the policy drivers, notably the pressure to improve the cost-effectiveness of care. However, few studies reflect on how ideas, values and beliefs are being challenged, confirmed and used to justify new roles and identities. We are interested in exploring this latter aspect of the movement of health care work, and argue that changing roles and identities create a culture of uncertainty which has important implications for the future of primary health care nursing.