The association of a bronchial or thymic carcinoid as a source for the ectopic production of adrenocorticotropic hormone (ACTH) has been reported since 1957, with approximately 72 cases in the literature. These patients are characterized by young age, long duration of Cushing's syndrome because of the inability to find the ectopic source, and a high incidence of hypophysectomy or adrenalectomy without curing the disease. A substantial number of patients, upon discovery of the thoracic ectopic source, are also found to have malignant carcinoid tumors with lymph node metastases. Fifteen patients have been explored for a presumed intrathoracic source of ACTH at our institution since 1983 and 14 carcinoids (13 bronchial, one thymic) have been resected. Seventy-one percent (10/14) of the patients appear cured with normal plasma ACTH levels 5 to 57 months after resection, despite a 50% incidence of positive lymph node disease. Management of these patients demands an aggressive evaluation to prevent unnecessary adrenalectomy or hypophysectomy and to allow earlier resections before these potentially curable malignancies metastasize. When the tumor is discovered, thorough exploration and complete lymph node mapping with resection must be performed.