Few data are available from follow-up studies on diabetic retinopathy in patients diagnosed with insulin-dependent (Type 1) diabetes mellitus in childhood and treated with conventional therapy. We report the results of conventional insulin therapy on development of diabetic retinopathy in 100 children and adolescents (47 females and 53 males), aged 8.3 +/- 3.5 (1.2-16.4) years at diagnosis of disease. Oral or intravenous fluorescein angiography was performed during a 3-19 year follow-up in all patients. Retinopathy was staged according to the criteria of the Italian Society of Diabetology (SID). During follow-up, retinopathy was observed in 28 patients (28%). At the end of follow-up, retinopathy was present in 23 patients and had disappeared in 5. Life-table analysis showed a median disease-free interval of 10.8 years. At 10 years from diagnosis the percentage of patients free of retinopathy was 66%. Poor metabolic control, age, and degree of pubertal development at diagnosis were the most important risk factors.