Background:
Complete atrioventricular septal defect (CAVSD) is composed of a primum atrial septal defect, nonrestrictive inlet ventricular septal defect and common atrioventricular (AV) valve. The aim of this study was to compare the result of surgical repair of complete atrioventricular (CAVC) before and after six months of age.

Methods:
Between January 2018 and December 2019 at Al-Azhar University and Atfal Misr hospital, 80 patients underwent CAVC repair. These patients were divided into 2 groups according to the age and each group is of 40 patients. These patients were managed by modified patch and double patch techniques.

Results:
In-group A, the mortality was four operative deaths, four patients with severs mitral reguigitation and mean pulmonary artery pressure 30 – 55 mmHg. While in the group B, there were seven operative deaths, two patients with severs mitral reguigitation and mean pulmonary artery pressure 50 – 65 mmHg.

Conclusion:
Early repair improve the pulmonary artery pressure with high incidence of surgical reintervention for Lt AV valve, while late repair improve the results for Lt AV valve but has a lower effect on the pulmonary artery pressure.