Among the secondary complications of diabetes, early stages of retinopathy and nephropathy are of foremost importance in paediatrics. Regular examinations of retinal status and of urinary albumin excretion therefore become necessary with the onset of puberty or after 5 years of diabetes duration. With fluorescein angiography, the first retinal changes can be expected after a median diabetes duration of 9 years, while the median time to clinically relevant background retinopathy is 14 years. This diagnosis is delayed by 4 and 6 years, respectively, if retinopathy is staged exclusively by ophthalmoscopy. Approximately 10 to 20 % of children may develop microalbuminuria, starting in early puberty. Several risk factors for the development of diabetic angiopathy have been identified. The degree of glycaemic control, both before and after puberty, appears to be of outstanding importance, but the contribution of other factors may be of varying relevance in the individual patient. These include arterial blood pressure, lipid abnormalities, sex steroids, smoking and genetic factors. Apart from the best possible metabolic regulation, early treatment with antihypertensive drugs has been shown to be beneficial in hypertensive adolescents but may also be renoprotective in normotensive adolescents with permanent microalbuminuria. However, the relatively high prevalence of intermittent and transient microalbuminuria in paediatric patients (2 and 3 % respectively), with unknown prognostic relevance, complicate the decision to start such treatment for a lifetime. Nevertheless, the early detection of risk factors and the implementation of appropriate intervention strategies are necessary to improve the long-term prognosis for children with diabetes.