Prediabetes, the presence of impaired fasting glucose/glycaemia and/or impaired glucose tolerance, affects about 16.4% of Australian adults. People with prediabetes are at increased risk of developing diabetes, and cardiovascular and other macrovascular disease. Management includes reducing cardiovascular disease risk factors, specifically lipid and blood pressure abnormalities, and smoking-cessation counselling. To help prevent progression to diabetes, people with prediabetes who are overweight or obese require intensive lifestyle intervention. Medication to help prevent diabetes may also be used, but only after a minimum of 6 months of lifestyle intervention. In people with prediabetes, there is no role for routinely testing: capillary blood glucose; glycated haemoglobin (HbA(1c)) levels; serum insulin or pancreatic C-peptide levels; or testing for ischaemic heart disease or the microvascular complications of diabetes. Follow-up assessment of glycaemia in prediabetes requires a formal 75 g oral glucose tolerance test, initially performed annually, with subsequent individualised testing frequency.