Abstract : Atrial septal defect (ASD) is one of the three most common types of congenital heart disease (CHD) in children. With the development of transcatheter closure technology is widely used in clinical practice. It is necessary to assess the quality of life of CHD patients besides mortality and morbidity. The aim of this study is to determine the quality of life children with ASD before and after transcatheter closure of ASD. An one group pretest-posttest study in 36 childrens with ASD where the defect was closed by transcatheter at H. Adam Malik hospital Medan from March 2021 to December 2021 and assessed the quality of life of the subject before and after transcatheter closure of ASD. All components of quality of life showed a significant difference between before and after transcatheter closure of ASD (p<0.05). After transcatheter closure of ASD only two people (5.6%) still showed impaired quality of life. By using the Spearman correlation test, it was shown that the quality of life with the domain of school function had a significant correlation with the size of the septal defect diameter (p=0.006). The correlation value (r) obtained is -0.446, but not with other function domains. There is a strong correlation between the age of septal defect closure and quality of life. There was difference between the quality of life children with ASD before and after transcatheter closure of ASD.