The object of this paper is to serve as a basis for discussion about priorities for further studies into the working of health centres. The result of a short-term enquiry sponsored by the King's Fund, it is concerned with describing the suggestions made of areas needing further study; providing a comprehensive list of studies that have taken place or are in progress; giving an outline of their progress and some problems they have come up against; discussing criteria that can be used in assessing priorities for further study and, on the basis of all these factors, suggesting areas which would benefit from further examination.