It is well known that non-toxic goiter is not uncommon in acromegaly, but hyperthyroidism only occasionally occurs. In addition, the risk for the development of a malignant process is increased, the most often seen is carcinoma of the colon. Thyroid carcinoma is not frequent, nevertheless the rate in these patients is higher than general population. In this article, a case of hyperthyroidism, papillar carcinoma and acromegaly is presented. We reviewed the literature an discussed the possible pathogenesis.