Many of the potential pitfalls of increasing purchaser plurality in the NHS are relevant in planning and developing general practitioner led locality commissioning. However, this involvement in commissioning or purchasing maternity care may actually provide the 'bite' necessary to move reluctant provider trusts more quickly towards services which meet the aims of 'Changing Childbirth' than health authorities have been able to do. Thus it is important to learn what lessons we can from the experience of practices actively trying to purchase maternity care. This paper describes: some selected characteristics of the general practice-based purchasers involved in the evaluation; their motivations and aims of taking part in the pilot and initial assessment of progress; the characteristics of maternity care experienced by some women registered with the general practice-based purchasers in comparison to those registered with practices not purchasing maternity care; contracting for maternity care in the study sites; and influences on the development of general practice-based purchasing and how changes are brought about.