This is the National Wastewater Drug Monitoring Program First Report. It provides statistically valid datasets of drug use and distribution patterns across a large number of sites in capital cities and regional areas. Wastewater analysis is widely applied internationally as a tool to measure and interpret drug use within national populations, with the current national program in Australia representing world best practice. Wastewater analysis provides a measure of one important aspect of national health—the demand for a range of licit and illicit drugs. An understanding of this behaviour allows governments to effectively direct resources to priority areas and monitor the progress of demand and supply reduction strategies