Abstract: Objective: To investigate clinical manifestations, methods of treatment and prognosis of thymic carcinoid tumors. Methods: From January 1960 to June 2006, 13 cases with thymic carcinoid were treated. There were 11 male and 2 female patients, ranging in age from 36 to 59 years with a mean age of 48.8 years and an average course of disease of 5.3 months. Results: In the group, 3 patients underwent complete resection, among which 2 survived for 8 years but one was not followed up past the 7th year and 1 survived for 7.5 years. Five patients received an incomplete excision and died of metastasis within 1 year. Two patients underwent exploratory thoracotomy, among which one received postoperative radiotherapy with a 13-year survival, and the other patient with ectopic superior vena cava syndrome (SVCS) died 3 months after exploratory surgery. Three patients were treated with chemotherapy and radiotherapy, among which 2 died within 1 year and 1 who received radiotherapy is currently surviving with ongoing treatment. Conclusion: The disease is pathologically classified as typical and atypical thymic carcinoid. The latter is highly malignant and has a poor prognosis. There are some difficulties in clinical diagnosis of typical thymic carcinoid. The characteristics of typical carcinoid include ultrastructurally dense core granules in the cytoplasm. The size of the granules vary from 600 to 5000 angstroms. Desmosomes can be found in some cases but the broad tonofilament and basal lamina of thymoma were absent. Electron microscopy may be needed for a differential diagnosis.