Atrioventricular septal defects (AVSD) are a group of malformations involving the atrioventricular (AV) septum and common AV junction. They are divided into complete, partial, intermediate and transitional AVSD. It is most commonly associated with Down Syndrome. All of them share a few common features. Complete AVSDs are also classified as balanced and unbalanced. Echocardiography is the primary imaging tool to diagnose these defects. Patients with complete and intermediate forms clinically present early and require surgical correction during infancy, whereas partial, and transitional forms become symptomatic in early childhood. Patients who are ineligible for complete surgical repair initially undergo palliative pulmonary artery banding. The surgical management of unbalanced AVSDs is complex. Most of these patients fall into either single ventricle, one and a half or bi-ventricular repair. Overall surgical outcomes for AVSDs are excellent. Left atrioventricular valve regurgitation is the most common reason for reoperation.