Abstract
Drug information or surveillance systems have been developed in an attempt to measure illicit drug use and predict new trends. In Australia, three systems are specifically designed to monitor drug use trends and related harm. These systems have their own strengths and weaknesses. This perspective offers a discussion of these facets. A series of case studies is used to highlight how surveillance systems can be effective in detecting and monitoring trends of use while highlighting the challenges these systems face. As indicated by the case study of ecstasy, such surveillance systems are effective and can provide unique information when a drug is detected and becomes 'established' in the market but the methodology of these systems is challenged when new drug classes emerge rapidly, as is illustrated by emerging psychotropic substances such as mephedrone.