From July 1992 a group of representatives from prison staff and NHS staff across London has worked together using the model of a learning network to develop a better understanding of the health needs of prisoners and to explore new ways of meeting those needs. This report: reviews the health status of prisoners in the United Kingdom; presents an innovative approach to strengthen the link between the prison service and the health service; and highlights the areas where the two services need to collaborate in order to ensure health improvement. Of great interest to staff in the prison service, health care purchasers and providers, this report will also be relevant to those involved in the development of learning networks.