Background: A lack of thyroid hormone present at birth is described as Congenital Hypothyroidism (CH). A difficulty with thyroid development or thyroid hormone production (dysgenesis) is most frequent in thyroid birth hormone insufficiency. It is one of the main causes of avoidable mental delay in infants This study aims to assess knowledge and awareness of Saudi parents towards complication of congenital hypothyroidism in Aseer region, KSA. Methods: A cross sectional study was conducted of general population of Aseer region. Data was collected by means of online questionnaire distributed online to be self-filled by parents. The study included 1086 participants. The collected data was entered and analyzed using the Statistical Package for the Social Science (SPSS Inc. Chicago, IL, USA) version 23. Descriptive statistics was performed. Results: All participants were from Aseer region, 39.5% of participants reported consanguinity between parents, 34.5% of all participants had heard of CH. 18.2% identified iodine deficiency during pregnancy as risk factor for CH. 22.6% identified excessive sleeping, 15.2% jaundice and 16% facial swelling. 60.2% did not know CH complications while 22.1% reported poor growth, resulting in short stature as a complication, followed by 14.4% Goiter, 14.1% delayed puberty, 13.5% mental retardation, 12.9% osteoporosis, 9.9% heart defects, and 4.6% bone fractures. 11.9% of all participants identified optimal time to start treatment to prevent complications as the first two weeks of the baby's life Conclusion: Parental knowledge of congenital hypothyroidism in Aseer is relatively unsatisfactory. Health campaigns and conferences to raise awareness is necessary looking to catastrophic complications caused by delayed diagnosis and management of the disease.