Primary pleural synovial sarcoma (PPSS) is an exceedingly rare, often aggressive malignancy that arises from the serous membrane lining the lungs and chest wall. The diagnosis requires histopathological analysis with immunohistochemistry; however, the neoplasm may mimic other pleural-based tumors (e.g., malignant mesothelioma, sarcomatoid carcinoma, malignant peripheral nerve sheath tumor, etc.). Most unique to PPSS is the presence of a specific genetic abnormality involving the SS18-SSX fusion gene, which plays a role in the development of cancer. The tumor typically exhibits rapid growth, and therefore, prompt diagnosis and intervention are pivotal. Treatment involves surgical resection, which offers the highest chance for survival, if feasible. Radiation and chemotherapy have been used and show varying results. Overall, the tumor demonstrates a poor prognosis due to its aggressive nature. This chapter reviews the pathophysiology, radiographic and clinical presentation, diagnosis, management, and prognosis.