Adrenal Incidentaloma is an adrenal tumor, which is unidentified before the imaging procedures conducted for an abnormality which is initially unforeseen as an adrenal disease. Symptoms and/or clinical signs of adrenal tumor do not have to be present prior to a diagnosis. Adrenal Incidentaloma can be divided into non-hypersecreting adrenal adenoma, hypersecreting tumor, primary adrenal carcinoma, other adrenal mass, and metastases. The majority of adrenal tumor is non-hypersecreting adrenal adenoma, but it is always considered as hypersecreting tumor until proven otherwise. Some conditions that can be found due to hormonal activity of adrenal incidentaloma is subclinical Cushing's syndrome, pheochromocytoma, aldosteronoma (Conn's disease), and several tumors which secrete androgen and sex hormone. Diagnostic approach of adrenal incidentaloma is focused on two main problems, which are, whether the lesion is hormonally active even though lacking characteristic clinical signs, and whether the lesion is benign or malignant; thus it needs hormonal and radiologic evaluation, even a fine needle biopsy. The management for adrenal incidentaloma includes surgical removal for hormonally active adrenal tumors, or inactive tumors with size less than 4 cm. Monitoring of tumor's hormone level and size are necessary for non-hypersecreting tumor without surgical removal.