This chapter discusses the microvascular complications. The microvascular complication of diabetes includes long-term complications of diabetes such as retinopathy, neuropathy, and nephropathy which affects small blood vessels. Long-term microvascular and neurologic complications are responsible for major morbidity and mortality in T1DM. Diabetic nephropathy is the most common microvascular complication in T1DM with earlier onset. Proteinuria is a typical characteristic of diabetic nephropathy and it is found in 15–40% patients with T1DM. Diabetic retinopathy is the leading cause for loss of vision among working age group in developed countries. It is strongly associated with other microvascular complications, specifically diabetic nephropathy, and proliferative diabetic retinopathy is strongly associated with cardiovascular events. Diabetic neuropathy can be defined as the disorder which does not have any additional reasons for peripheral neuropathy other than diabetes, which can be autonomic or somatic. In addition to good metabolic control to prevent and to delay microvascular complications in T1DM children and adolescents, early diagnosis and treatment of hypertension and dyslipidemia are also important. Intensive therapy in T1DM children at an early age can prevent micro- and macrovascular complications.