A 29-year-old female was admitted to our hospital complaining of severe dry cough and low-grade fever. A chest roentgenogram and a chest computed tomographic scan revealed a huge tumor and massive pleural effusion in the left pleural cavity. Pathological examination revealed spindle shaped malignant cells. SYT-SSX fusion gene transcripts were detected, so we diagnosed the tumor as a synovial sarcoma in the pleural cavity. After neoadjuvant chemotherapy we resected the tumor completely. A synovial sarcoma in the pleural cavity is extremely rare. To the best of our knowledge, this is the thirteenth case, and the first case to undergo neoadjuvant chemotherapy and complete resection. Because a synovial sarcoma in the pleural cavity has a poor prognosis and is characterized by a high incidence of recurrence, we must carefully follow up this patient.