Lowering of the legal minimum drinking age to 18 years in two Australian States significantly increased male juvenile crime by 20–25%. In the case of a third State the limited data available yielded similar results. Particularly as the above increases were over and above those for between-State control groups of the same age, and older control groups within the same State, the findings appeared to be valid. For the females the results varied from State to State. From the view point of preventing alcohol-related juvenile crime, a 20 or 21 year legal minimum drinking age is preferable to an 18-year-old limit.