Adrenal masses discovered during cross-sectional imaging performed for nonadrenal indications have become known as adrenal incidentalomas. The prevalence of adrenal incidentalomas is 4.5% on cross-sectional imaging and are found in 1–8% of autopsies. Approximately 70% of adrenal incidentalomas are benign adenomas, 20% are other types of benign lesions, less than 10% are malignant (mostly metastatic spread from other cancers), and 1% are primary adrenocortical carcinoma (ACC). Any adrenal incidentaloma found to be hormone-producing or to have malignant features should be referred to a surgeon to evaluate for adrenalectomy.