For a variety of reasons, GPs are working more and more with unfamiliar patients. The proposed new British GP contract stipulates that in future patients will register with a practice, rather than with a named GP and a recent new definition of general practice did not mention continuing care. There has been persistent confusion about the definition of continuity of care. Evidence for the benefit of patients usually seeing the same doctor is still limited. In this paper we describe some discrete elements of continuity, emphasize the importance of interpersonal continuity and suggest how this may work. The contributions of informational continuity (especially good records) and of excellent consulting skills are put in context. We conclude that further evidence is needed to demonstrate the added value of interpersonal continuity in general practice and that this needs a clear theoretical basis. We propose that such a theory will define the concept of multi-dimensional diagnosis as the key strength of our discipline and that continuity, especially interpersonal continuity, is an important factor in achieving this economically and in a way which satisfies both patients and professionals.