Background :Type 1 diabetes, previously known as juvenile diabetes or insulin- dependent diabetes, is a form of diabetes characterized by the body’s inability to produce insulin owing to the autoimmune destruction of the insulin-producing beta cells in the pancreas. Klotho (KL), known as an anti-aging protein, was discovered recently to have a multitude of biological effects. Major attention has been paid to the role of α-klotho (α-KL) in diabetes and its relation with diabetic nephropathy. The circulating form of α-KL, named as soluble KL, functions as an endocrine substance that exerts heterogeneous actions, including the modulation of renal function upon hyperglycemia, regulation of cell compensation, down regulation of inflammation and anti-oxidation effects. Objectives: The aim of this work is to study plasma KL and plasma copeptin in adolescents with type 1 diabetes and their relation to microvascular complications. Patients and methods : This study was conducted in diabetes outpatient clinic in national institute of diabetes and endocrinology. The sample of 117 patients was divided into three groups: diabetes group, with 39 patients; diabetes with complication group, with 39 patients; and healthy controls, with 39 participants. Results : Our study shows significant elevation of plasma copeptin level in type 1 diabetic adolescents, which was also significantly higher in the presence of microvascular complications particularly diabetic kidney disease (P=0.000). Although plasma KL is found to be significantly higher in type 1 diabetes without complications group, its level is dropped in the diabetes with Conclusion : Plasma KL and plasma copeptin can be used as novel biomarkers for predicting early kidney injury in type 1 diabetic adolescents. Keywords: klotho, microvascular, plasma copeptin, type 1 diabetes mellituscomplications group (P=0.005).