This paper analyses the role chaplaincy plays in providing religious and spiritual care in the UK's National Health Service. The approach considers both the current practice of chaplains and also the wider changes in society around beliefs and public service provision. Amid a small but growing literature about spirituality, health and illness, I shall argue that the role of the chaplain is changing and that such change is creating pressures on the identity and performance of the chaplain as a religiously authorised health worker. I shall question whether either orthodox belief or religious belonging have any significant bearing on the patients' demand for chaplaincy services. Utilising an example of chaplaincy work I shall argue that patient need constitutes the strongest platform for both practice development and an articulated understanding of what chaplains bring to health care. Drawing on a case study the definition and interpretation of spiritual need will be discussed in relation to chaplaincy practice. In conclusion, I shall set out the case for effective research to establish with greater precision the detail of the chaplain's practice within a state-funded health system.