This Monograph (No. 10) provides a description and review of the routinely-collected data sources available in Australia that capture information on illicit drug use and related harms. Based on work undertaken at the National Drug and Alcohol Research Centre and Turning Point Alcohol and Drug Centre, it is intended as a reference document to provide interested persons with a guide to the type and nature of the information available in Australia. It reviews available data across four main domains; patterns and prevalence of use, health consequences, market characteristics and drug crime. For a review of information available on the economic aspects of illicit drug use and harm see Monograph 09 of this series.