Diabetes is a chronic (long-term) condition that can have a major impact on life expectancy and quality of life, especially if undetected or poorly controlled. It is estimated that in 1999-2000 around 1 million Australians (7.4% of the population) had diabetes. This bulletin investigates medicines used in the control of blood glucose levels ('antidiabetic medicines') as well as those used for related reasons such as the prevention or control of common diabetes complications.