There is a lack of information regarding the use of novel psychoactive substances (NPS) in Western Australia. The aim of this study was to pilot-test an online survey to obtain data on the prevalence of NPS and other drug use by young Western Australians aged between 18 and 35 years. The Young Adult Drug and Alcohol Survey (YADAS) was a questionnaire deployed online for a period of six months. Participants were recruited via a combined targeted sampling and snowball methodology. There were 472 valid responses. Overall lifetime use of NPS was relatively high (17.6%), while use in the last year was lower (6.6%). These proportions were comparable to that of cocaine use. The most popular NPS were the synthetic cannabinoids. The proportions of respondents drinking alcohol at risky levels, mixing alcohol with energy drinks, and using pharmaceuticals such as ADHD medications for non-medical reasons were high. The YADAS is the first survey to ascertain the prevalence of use of numerous types of NPS in a large sample of young Western Australian adults. The utilization of an online survey methodology yielded valid results as compared to more intensive surveys, and enables researchers greater flexibility in being able to capture current trends. Keywords — alcohol consumption, community survey, illicit drugs, novel psychoactive substances, pharmaceuticals