Abstract: The harmful use of AOD (that is, any use that impacts negatively on the health, social and emotional wellbeing of users themselves and others) is a significant public health problem for the Australian community as a whole and incurs significant economic costs. In this paper, we focus on one aspect of this wider problem and provide an overview of: • harmful AOD use within Indigenous communities • its relationship to the health gap between Indigenous and non-Indigenous Australians • strategies that are known to be effective in reducing harm • the necessary conditions for such effectiveness.