This study investigated the association between presence of mental illness, detected by an increased level of Kessler Psychological Distress Scale score, and prevalence of exposure to opportunity to obtain illicit drugs among adolescents and young adults aged 12-24 years using data collected by the 2007 Australian National Drug Strategy Household Survey (N = 2,663). Adolescents and young adults with mental illness have increased prevalence of exposure to drug use opportunity. Higher exposure to opportunity to obtain illicit drugs among people with pre-existing mental illness may further contribute to the co-existence of drug dependence and other mental disorders that are frequently reported in the literature.