Aims and MethodProgramme budgeting and marginal analysis (PBMA) is a recognised tool for commissioning healthcare. the objectives of this project were to test the acceptability, data availability and practical value of PBMA within the sphere of mental health. the PBMA methodology was applied to the consideration of Norfolk Primary Care Trust's National Health Service expenditure on mental health for the fiscal year 2006/7.ResultsThe project successfully attracted the interest of, and contribution from, important stakeholders with the exception of general practitioners. the process led to the identification of areas for disinvestment, releasing funds to be made available for the development of new services, or enhancement of existing services.Clinical ImplicationsProgramme budgeting and marginal analysis is a useful structured tool for the commissioning of mental health services. It is essential, however, that psychiatrists fully engage with the process in order to have an influence over the future direction of mental health services.