The number of studied patents was 100 constituting of 61 (60.4%) females and 40 (39.6%) were males. Females were more commonly effected than males.Agenesis as a subcategory of dysgenesis was the most common diagnosed (43.3%) followed by ectopic ( 26.66%), then lingual (13.3%) following by hypoplasia ( 11. 6%), while the least common diagnosed were aplasia ( 3.3%).Incidence among years of follow up, showed slight increase and decrease with no steady increasing or decreasing pattern in both dysgenesis and dyshormonogenesisMost of neonates were asymptomatic during the neonatal period and in their first visit in the outpatient, which makes hypothyroidism in the new born period is almost always overlooked, and delayed diagnosis leads to severe outcome.So absence of symptoms and signs, makes screening, scintigraphy and thyroscan main tools of diagnosis.Screening is the ideal primary, easy, cost effective method of detection of congenital hypothyroidism, whatever permanent or transient.Ultrasound and scintigraphy were tools of etiological diagnosis of the disease. However sensitivity and specificity of U/S compared with scintigraphy in diagnosis is low, U/S failed to diagnose high percentage of ectopic cases and non functioning thyroid gland, only detecting anatomy of thyroid.