Ectopic ACTH secretion represent 10 to 15% in the causes of Cushing's syndrome. Carcinoid tumor of the thymus is a rare neoplasm and is currently believed to arise from population of thymic cells of neural crest origin. We present the case of a 43-year-old man with a corticotropin hormone (ACTH) secreting thymus carcinoid. 111In-octreotide scintigraphy demonstrated an intense uptaken on the lesion. The surgical specimen measured 17 x 18 x 18 cm and weighed 1. 25 kg. Postoperatively the patient was treated by chemotherapy and radiotherapy. A follow-up 111In-octreotide scintigraphy was normal. Very few scintigraphic images of these lesions have been published in the literature. Somatostatin receptor scintigraphy can be successful in the detection and follow-up of ACTH-secreting neuroendocrine tumors.