Collaboration is one of the cornerstones of health promotion, with the literature indicating a range of circumstances under which it can either succeed or be undermined. In New Zealand in the 1990s, a market structure for health made collaboration of all kinds exceptionally difficult. This paper traces the efforts of a group of nutrition agencies (Agencies for Nutrition Action) to defy the popular wisdom and persist with collaborative efforts. The agencies were unsuccessful in their attempts to develop joint campaigns, but were very successful in advocacy and intersectoral action that did not threaten the position of individual agencies in the competitive environment. It is possible that the collaboration could have been more effective if agencies had been willing to surrender some autonomy and commit themselves to supporting a more independent new organization. However, this would have compromised not only their individual integrity but also their commitment to a relationship of equals. In 'holding fast' to a belief in health promotion, the ANA resisted being coopted by a now discredited market system, and emerged with its integrity and that of its participating agencies intact. ANA is now well positioned to work within an emerging policy environment that is more supportive of health promotion.