The costs of community-level interventions are rarely reported, although such insights are needed if intervention research is to be useful to practitioners seeking to understand what might be involved in replicating interventions in different contexts. We report the costs of a 2-year community-based intervention to promote the health of recent mothers in Victoria, Australia. Program of Resources, Information and Support for Mothers was an integrated programme of primary care and community-based strategies. It had health care professional training, health education and community development components as well as an emphasis on creating 'mother-friendly' environments. Costs included the programme costs [primarily the salaries of the community development officers (CDO) in the field] and also 'induced' costs that relate to the CDOs' successes in attracting additional resources to the intervention from the local community. The total cost averaged A$272,490 per rural community and A$313,900 per urban community, equivalent to A$172.40 and A$128.70 per mother, respectively. For every A$10 of public funds initially invested in the project, the CDOs were able to attract a further A$1-2 worth of local resources, predominantly in the form of volunteer time or donated services.