Type 2 diabetes is an increasing problem in children. Two decades ago it had been described only in selected groups, e.g. the Pima Indians. Childhood type 2 diabetes appears to be similar to the metabolic syndrome in adults and is characterized by obesity, hyperglycaemia and insulin resistance. It can present a diagnostic challenge in children, as they can present with diabetic ketoacidosis; the measurement of autoantibodies and C-peptide levels may be helpful. The logarithmic association between the risk of complications with increasing glycaemia which has been established for adults with type 2 diabetes is likely to hold true for children but the conclusions of trials in adults must be extrapolated with caution. Little is known about the onset and progression of macrovascular disease in affected children but it is almost certain that they will develop an excess of premature cardiovascular disease. However, the importance of reducing glycaemia in younger adults with diabetes, in order to minimize the incidence of microvascular complications, has been unequivocally demonstrated in the Diabetes Control and Complications Trial (DCCT). Diet and exercise have a major role to play in the treatment and prevention of type 2 diabetes in children as well as adults – the escalation of type 2 diabetes throughout the developed world is a major public health problem. Extrapolating data from adults, metformin appears to be the logical first-line treatment in children with type 2 diabetes; sulphonylureas are also used but neither of these agents have been evaluated in trials in children and are not licensed for such use. With regard to other newer agents, it seems wise to use well-established drugs with a long track record and for which the long-term safety data are available.