A significant factor contributing to the problem of underage drinking is the 'secondary supply' of alcohol to minors. Secondary supply by parents for consumption in private settings is legal in most states of Australia including NSW. The NSW Police Force, in partnership with the Central Coast Health Promotion Unit, developed a community-based intervention to address the issue of secondary supply of alcohol to minors ('Supply Means Supply'). This paper reports on a series of focus groups to examine in more depth the drivers of attitudes towards secondary supply to minors, and to assess responses to the Supply Means Supply campaign messages. Twenty focus groups were conducted with teenagers, young adults and parents/carers in Wollongong, Penrith and Dubbo.