Diabetes is on the increase worldwide. The incidence of both type 1 and type 2 diabetes has shown a rise, in parallel with a notable increase in the incidence of a new expression of the disease in children and adolescents, with the characteristics of a mixture of the two types of diabetes, and referred to as 'double diabetes'. Insulin resistance and obesity, together with the presence of markers of pancreatic autoimmunity - namely, autoantibodies to islet cell antigens - typically define this condition. However, recognition of double diabetes can pose problems. In most cases, a reduction in the 'autoimmune load' and an increase in the 'metabolic load' are helpful for attaining a correct diagnosis in a diabetic child.