Background: The treatment of thymoma or thymic carcinoma with pleural dissemination remains controversial due to the unpredictable natural history of this tumor. Our study discusses the combination of cytoreductive surgery with hyperthermic intrapleural chemotherapy to treat thymoma or thymic carcinoma with pleural dissemination. Methods: From February 2008 to January 2010, there were four patients with pleural thymoma metastases undergoing cytoreductive surgery and intrathoracic hyperthermic perfusion with chemotherapy at our department. After video-assisted thoracoscopic surgery, the hyperthermic perfusion system was set up for hyperthermic intrapleural chemotherapy. The thoracic cavity was perfused at a speed of approximately 1.8-2.3 L/min with 0.9% normal saline. The intrathoracic temperature remained between 42 degrees C and 43 degrees C. The perfusion process lasted for 2 hours. Results: There were no perioperative deaths. During the hyperthermic perfusion, the patient's core temperature varied from 36.3 degrees C and 39.3 degrees C and pulse varied from 59 beats/min and 126 beats/min. Intraoperative sinus tachycardia occurred in two elderly patients. No hematologic toxicity and nephrotoxicity was observed within 1 week after surgery. Postoperative pneumonia occurred in one elderly patient. Patients were followed up for 1-4 years. One elderly patient died of heart failure 1 year after surgery. There were no patients with local recurrence or metastases to distant sites. Conclusions: Cytoreductive surgery and intrathoracic hyperthermic perfusion with chemotherapy may be effective in treating thymoma or thymic carcinoma with pleural dissemination and has an encouraging impact on the patients' long-term survival.