Strumal carcinoid is an unusual form of monodermal ovarian teratoma with thyroid-like follicles admixed with typical carcinoid tumor patterns. We encountered a case of this neoplasm in a patient with multiple endocrine neoplasia, type IIA (Sipple's syndrome), including a medullary thyroid carcinoma diagnosed 24 years previously. During evaluation of bilateral adrenal pheochromocytomas, a unilateral left ovarian strumal carcinoid was discovered. Subsequently, the patient had a parathyroid adenoma excised. The ovarian tumor was immunohistochemically reactive for neuron-specific enolase, chromogranin, synaptophysin, and serotonin, but did not stain for calcitonin. The follicular structures stained for thyroglobulin. This unusual case shows that ovarian strumal carcinoid, like carcinoid tumors at other sites, may arise in association with multiple endocrine neoplasia.