AIMS: Type 2 diabetes mellitus has never previously been described in UK children, although an increasing incidence in childhood is recognized in international studies. The prevalence of obesity in UK children is increasing and is a recognized risk factor for the development of diabetes. The aim of this study was to identify and characterize children with Type 2 diabetes in the West Midlands and Leicester. METHODS: Children were identified by contacting paediatricians responsible for diabetes in five hospitals. Details were collected on demographics, mode of presentation, investigations and treatment on a standard proforma. RESULTS: Eight girls were identified with Type 2 diabetes, aged 9-16 years and who were of Pakistani, Indian or Arabic origin. They were all overweight (percentage weight for height 141-209%) and had a family history of diabetes in at least two generations. They presented insidiously with hyperglycaemia and glycosuria without ketosis and five were asymptomatic. Islet cell antibodies measured in seven patients were negative. Four had acanthosis nigricans which is a cutaneous marker of insulin resistance and the other four had high plasma levels of insulin and/or C peptide. These patients are distinct from those with maturity-onset diabetes of the young (MODY). All were initially managed with dietary measures, seven have been treated with oral anti-diabetic agents of whom two have subsequently required insulin. CONCLUSIONS: These are the first UK case reports of Type 2 diabetes in children. Paediatricians need to be aware of the risk of Type 2 diabetes developing in childhood in high-risk ethnic groups, particularly in association with obesity and a positive family history.