Background: Thyroid hormone deficiency at birth is most commonly caused by a problem with thyroid gland development. Aim of the study: Wasto assess mothers' knowledge and practice regarding care of their children with congenital hypothyroidism. Research design: A descriptive research design was used to carry out the study. Setting: The study was conducted at Outpatient Clinics, in Specialized Pediatric Hospital at Benha City affiliated to Benha University Hospital Sample: A convenience sampling of 150 mothers and their children with congenital hyperthyroidism. Tools: Two tools were used: Tool 1- A structured interviewing questionnaire: This tool consisted of three parts: I: Personal characteristics of the studied mothers. II: Personal characteristics of children. III: Mothers' knowledge regarding congenital hypothyroidism. Tool 2: Mothers' reported practice sheet. Results: Almost three quarters of mothers had unsatisfactory knowledge about congenital hypothyroidism, while almost two thirds of studied mothers had adequate reported practice regarding care of their children with congenital hypothyroidism. Conclusion: There was a highly statistically significant relation between total knowledge and practice of mothers and their personal characteristics. Moreover, there was a positive statistically significant correlation between total knowledge and total practice about congenital hypothyroidism. Recommendations: Health educational program for raising awareness of mothers through health education regarding care for hypothyroidism child can contribute to well-being of children.