Community participation in health promotion is one of the central tenets of the WHO's Health For All strategy. Throughout the United Kingdom, 'Health For All' projects have been established and efforts dedicated to the pursuit of community participation in health promotion. Despite this zeal, the deceptively simple notion of 'community' is one of the most contested in the social sciences. Taking this as its point of departure, this paper reviews the meanings of 'community' in social sciences and health literatures. Based on empirical data, it then explores meanings of 'community' for people who are involved in generating community participation in health promotion in the context of four U.K. Health For All projects. A wide variety of different meanings are found; what they share in common is that they are each constructed by people who regard themselves as 'non-members' of these 'communities' and that the views of the putative 'members' are not taken into account in their construction. This substantially differs from meanings of community constructed by their 'members', as represented by Anthony Cohen, where community members' perceptions of sharing are central to the delineation of boundaries. This paper argues that there is a fundamental difference between the construction of communities by 'members' and 'non-members'. In the former case notions are sharing are integral to the construction, in the latter case they are assumed. In the final part of the paper we examine informants daily experiences of operationalising the 'communities' which they construct and argue that commonly their assumptions of sharing prove unfounded. We conclude by arguing that recognition of the differences in the construction of communities by members and non-members is essential, not least because it demands a fundamental rethinking of the notion of community participation in health.