DiGeorge syndrome is a common genetic disorder that frequently results in congenital heart defects such as truncus arteriousus, coarctation of the aorta, interrupted aortic arch, tetralogy of Fallot, pulmonary atresia with VSD, and several others. The defect is usually due to a deletion in the long arm of chromosome 22. Approximately 25% of patients with DiGeorge have a congenital heart defect. These patients also have varying degrees of thymic hypoplasia with associated T cell dysfunction. They are at increased risk of infections and can be at risk for opportunistic infections when the degree of T cell dysfunction is severe. Children undergoing cardiac surgery are at risk for infections in the post-operative period, prolonging hospital stay and increasing morbidity and mortality. The patient with DiGeorge syndrome may have higher rates of infection due to associated immune system dysfunction, however, this has not been previously reported from a large group of DiGeorge syndrome patients. Children's Healthcare of Atlanta follows over 200 patients with DiGeorge syndrome, with the majority having previously undergone cardiac surgery. This group of patients may benefit from more extensive antibiotic prophylaxis following surgery if they indeed have significantly higher rates of infection, but the true incidence needs to be determined.