Primary care groups (PCGs) and primary care trusts (PCTs) are the way forward for primary care in the UK. These groups of general practitioners (GPs) and community nurses, organized along geographical lines, will need to forge relationships with other organizations and key players to a much greater extent than has been necessary hitherto. Currently PCGs most closely resemble the total purchasing pilots (TPPs), which have been the subject of a national evaluation. This paper reports on the evidence collected by interviewing key stakeholders – lead GPs, health authority (HA) leads, project managers and social services representatives – about how relationships developed in TPPs and how this might be relevant to PCGs and PCTs. The importance of good relationships with HAs was recognized by the TPPs, and the HAs were seen as having an important strategic role. Relationships with social services were slow to start for historical reasons, and had not progressed particularly far by the end of the study. Similarly, involving patients and the wider public in TPPs was problematic, and there was a lack of guidance about the most appropriate ways of proceeding. The evidence suggests that progress will be slow and the problems encountered by TPPs are likely to become apparent as PCGs develop, and with the transition to trust status. There is much for the primary care groups and trusts to learn from the TPPs.