An incidentally discovered adrenal mass involves two main questions: the first is the evaluation of the hormonal activity of incidentalomas, that by definition are considered clinically silent. The second problem is to establish preoperatively the biologic behaviour of the masses, whether they are benign or malignant. An essential endocrinological screening of these masses includes the 24 hour urine VMA determination, serum potassium level, and a 1 mg overnight dexamethasone suppression test. Furthermore, the recent observation of a possible partial deficit of 21-hydroxylase suggests the advantage of 17-hydroxyprogesterone dosage after ACTH stimulation. At present no biochemical or radiologic markers can reliably distinguish benign from malignant masses. For this reason the association of imaging study with scintigraphy seems to be helpful, providing "concordant" or "discordant" patterns with CT images. As regard to therapeutic indications, the resection of all hypersecretive masses, proved malignant or increased in diameter tumors is suggested. As regards to biochemically silent lesions, the tumor size has been deemed to be the most helpful determinant of the nature although controversy remains over the size cutoff below which the masses can safely be presumed to be benign and therefore observed. The threshold to proceed surgically has been based on the perceived risk of cancer balanced against the operative risk. However it seems reasonable to recommend excision or surgical exploration for hormonally silent tumors greater than 3 cm, particularly in younger patients. According to personal opinion the laparoscopic approach might represent the gold standard in the treatment of incidentally discovered adrenal masses.