Objective To understand the level of medical fear in hospitalized children with congenital heart disease and to explore its influencing factors.Methods A convenient sampling method was used to select 110 hospitalized children with congenital heart disease from a level-A tertiary hospital in Nanjing from October 2021 to July 2022,and the General Information Questionnaire and the Child Medical Fear Scale(CMFS)were used to investigate medical fear and its influencing factors of them.Results The highest scoring items in CMFS for children with hospitalization of congenital heart disease were the long hospital stay,injections,and absence of the family members(P<0.05).The univariate analysis showed that age,perioperative stage,place of residence,whom do children often lived with,and the extent to which parents have knowledge of the condition to meet the child's needs were the factors that influenced medical fear in hospilalized children with congenital heart disease(P<0.05).The multiple linear regression analysis showed that young age(P=0.009),frequent living with parents(P=0.026),and city of residence(P=0.034)were unfavorable influencing factors of medical fear in hospitalized children with congenital heart disease.Conclusion For hospitalized children with congenital heart disease,medical staff should pay attention to the medical fear,and improve the hospital's medical environment.Enough sufficient psychological counseling and care should be provided during medical procedures.Health education for parents of children with congenital heart disease should be strengthen.Thus,the medical fear level of hospitalized children with congenital heart disease can be alleviated from multiple perspectives and comprehensively,and the children can have a speedy recovery.