212 insulin dependent young diabetics with mean age of 16 yr and mean diabetes duration of 9 yr, have been examined for prevalence of subclinical signs of microvascular disease. Prevalence of retinopathy is increased in subjects of older age when matched for diabetes duration. Subclinical abnormalities of peripheral nervous system, identified by neurophysiological techniques, are present in about 20% of patients. These abnormalities are mainly related to metabolic control as evaluated by HbA1c determination. Albumin excretion rate over 10 mcg/min is observed in about 40% of subjects and is related to increased blood pressure values and poor metabolic control.