PRINCE2, which stands for Projects in Controlled Environments, is a project management method covering the organisation, management, and control of projects and is widely used in both government and commercial IT and building projects in the UK. This paper describes the application of PRINCE2 to the management of large clinical trials (specifically, of a Phase III trial of a candidate microbicide to prevent vaginally acquired HIV infection). It reviews the challenge of ensuring that the project management tools add value to the project overall and are not perceived as an overly administrative burden. It reviews the requirement for high level summary reports for use by an executive committee and funding bodies, highlighting the reasons for taking this approach--in particular, not only to manage the science, but to link expenditure to activities at geographically separate trial sites and to key performance indicators, and to provide tools for monitoring risks and possible re-alignment of budgets to reflect changing activities and outputs by collaborators. The paper considers the wider costs and benefits to researchers and funders of taking this approach and explores implications for research administrators and managers at institutions involved in large, complex collaborative research projects, whether clinical or not. (Contains 3 tables and 2 figures.)