The present article describes a qualitative study designed to evaluate the effectiveness of a peer-support intervention to promote breast-feeding in a deprived area. The aims of the study were to: explore stakeholders' experiences of the intervention; explore the development of a 'culture' of breast-feeding; and consider the potential of the initiative for building community capacity. The methods used in the research were in-depth interviews, diaries and direct observation. The findings describe the social and cultural barriers to breast-feeding experienced by women, and the ways in which professional and lay participants in the peer-support project attempt to reduce them. The advantages of partnership working between health professionals and lay volunteers are then explored. These include: sharing the workload; providing an informal tier of support to mothers; and importantly, offering support and advice stemming from personal experience. For lay supporters, the benefits of taking part in the project range from personal satisfaction at being recognised as skilled, to gains in confidence which potentially open up further educational and training opportunities. In conclusion, it is suggested that the 'success' of such interventions is unlikely to be captured solely by monitoring breast-feeding rates, but needs to take into account the wider context of community development.