There are two problems that needs to be addressed in cases of an adrenal incidentaloma. The first is to decide whether the adrenal mass is benign or malignant, and the second is to determine whether the mass is hormonally active or not. A 17-year-old male was admitted with the complaint of progressive weight gain. Abdominal ultrasonography was performed for elevation in transaminases which revealed a hypoechoic mass located in the left adrenal gland. Hormonal investigations revealed an increase in fractionated catecholamine and metanephrine levels in 24-hour urine. Surgery was performed and pathological examination was in accordance with pheochromocytoma. Mutation analysis was carried out. This is a rare case of pheochromocytoma presenting as adrenal incidentaloma during adolescence. In view of this case, we review the approach to incidentally discovered adrenal masses and the approach to pheochromocytoma. A mutation analysis should be performed on all cases with pheochromocytoma that are diagnosed below age 20.