An I-131 metaiodobenzylguanidine (MIBG) scan was performed in a patient with a familial history of multiple endocrine neoplasia (MEN) type 2 and recurrent medullary thyroid carcinoma (MTC). The scan revealed a mediastinal metastasis from her MTC and there was also an imaging pattern of bilateral adreno-medullary hyperplasia. Although the literature indicates that I-131-MIBG scanning is not sufficiently sensitive for the detection of MTC, this procedure has proven to be of value in the management of chosen patients with MEN-associated MTC.