The aim of the present study was to detect the frequency of thyroid autoimmunity and thyroid dysfunction in a cohort of Type 1 diabetics conveniently selected from the Diabetic Endocrine Metabolic Pediatric Unit at the Children's Hospital of Cairo University. Patients were included in the study as they presented to the unit. We also aimed to study possible epidemiologic risk factors, including family history of autoimmune disease, parental consanguinity, age, sex, and duration of diabetes. They included 26 females (52%) and 24 males (48%), there age ranged from 4 to14 years with mean 9.85 years (SD ± 2.6), duration of diabetes ranged from 0.16 to 10 years (mean 2.73 years SD ± 2.71), height standard deviation score (HSDS) from -2.4 to + 3.0 (mean -0.185 SD ± 1.8).