The endocrine system plays an intricate role in the regulation and modulation of cardiovascular function. Several hormones including thyroid, mineralocorticoid, glucocorticoid, arginine-vasopressin (AVP), and growth hormone (GH) have been investigated as adjunctive therapies in pediatric cardiac disease. Thyroid hormone supplementation appears to be safe in neonatal and pediatric post-operative cardiac patients, but the benefits have been modest and inconsistent. Glucocorticoids appear to decrease the inflammatory response associated with cardiopulmonary bypass in children, but have little effect on clinical outcomes. The role of AVP in pediatric shock remains limited due to inconsistent trial results and its potential side effect profile. Although mineralcorticoids are commonly used to treat neurocardiogenic syncope, little to no benefit has been demonstrated in controlled trials. GH normalizes altered cardiac function in children who are GH deficient, but its effectiveness in the treatment of heart failure has been variable. Overall, the use of these hormones in a variety of pediatric cardiac conditions generally appears to be safe, but their efficacy for relieving symptoms, improving cardiac function, and improving clinical outcomes remains unclear.