Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant tumor syndrome. Thymic carcinoid tumors in MEN1 are not common and their natural history is little known. But development of thymic carcinoid tumors is important because in 1993, they were identified as a frequent case of death. There has not been a report of case in Korea so far. We encountered a case of thymic carcinoid in MEN1. A 42 year old man was referred presenting with diabetes of 12 years duration. Abnormal findings in his blood chemistry were hypercalcemia and hyperprolactinemia. 99mTc-sestamibi scintigraphy showed parathyroid adenoma and hyperplasia. Sella MRI showed pituitary macroadenoma. Abnormal CT scan demonstrated multiple pancreas islet cell tumors, bilateral adrenal tumor and thymoma. Subtotal parathyroidectomy with thymectomy was perfomed and thymic carcinoid was confirmed. This is the first report of thymic carcinoid with MEN1 in Korea.