Adrenal tumors are very common, with the majority being non-hypersecretory and benign and less than 1% being malignant. Most primary adrenal tumors are sporadic, but may be associated with other endocrine and familial disorders, especially pheochromocytoma. All patients with “sporadic” pheochromocytoma should be screened for MEN-2 and Von Hippel-Lindau disease. As in many endocrine tumors, there are no uniform definitive histologic criteria to distinguish malignancy, which is dependent on the clinical behavior of the tumor and is accurately diagnosed in the presence of adjacent organ invasion, recurrence, or distant metastasis. Surgery remains the cornerstone and the treatment of choice for functional and primary malignant adrenal tumors, both for cure and palliation, with low morbidity and mortality.