Neoplasms of the adrenal gland may cause increased hormone activity, which has profound effects on the growing child. The adrenal gland should be viewed as two functionally separate glands: the adrenal medulla and adrenal cortex. Neoplasms of the adrenal cortex secrete excess glucocorticoids, mineralocorticoids, or androgens. Adrenal medulla neoplasms generally secrete excess catecholamines. Understanding the anatomy, embryology, and physiology of the adrenal cortex and medulla allows surgeons to diagnose these tumors, prepare the patients for surgery, and treat them effectively after resection. Because adjuvant therapy for adrenal cortical and medullary tumors is of limited effectiveness, the surgeon's role in the treatment of these neoplasms is extremely important.