The statutory function of local health councils in Scotland (and of community health councils in England and Wales) is to represent the interests of the public in the health service. This article, based on data from a fouryear research project financed by the Scottish Office, examines official and participants' assumptions and claims about the legitimacy of health councils, as at present constituted, to carry out this function. Clarification of the basis of their legitimacy would assist, it is argued, in the resolution of a central dilemma: How are councils to represent the interests of the public? The conclusion is reached that inadequate thought was given to developing theoretically sustainable arrangements. Several interpretations of representation are admixed in the rationale for the present system and they cannot be aggregated to produce a coherent defence of it.