INTRODUCTION AND AIMS: In order to monitor trends in illicit drug use among youth, surveillance of drug use behaviours among a variety of populations in different settings is required. We monitored drug use among music festival attendees. DESIGN AND METHODS: Cross-sectional studies of young people’s reported drug use were performed at a music festival in Melbourne from 2005 to 2008. Self-administered questionnaires collected information on drug use, demographics and other risk behaviour. RESULTS: From 2005 to 2008, over 5000 questionnaires were completed by people aged 16-29; 2273 men and 3011 women. Overall, use of any illicit drug in the past month was reported by 44%. After adjusting for demographic and behavioural characteristics, the prevalence of recent illicit drug use decreased significantly from 46% in 2005 to 43% in 2008 (OR 0.92, 95% CI 0.87-0.97). After adjusting for age and sex the downwards trend was repeated for amphetamines and cannabis, but a significant increase in prevalence was observed in hallucinogen, ecstasy and inhalant use. Drug use was more common among men, older participants and those engaging in high-risk sexual behaviour. DISCUSSION AND CONCLUSIONS: Illicit drug use was much more common in this sample than in the National Drug Strategy Household survey, but the direction of trends in drug use were similar; drug use prevalences were much lower than in the Ecstasy and Related Drugs Reporting System, the Illicit Drug Reporting System or National Needle and Syringe Program Survey. Music festival attendees are a potentially useful group for monitoring trends in illicit drug use.