Introduction: Synovial sarcoma is an aggressive neoplasm described in several locations but is uncommon in the lung. Method: We report a case of biphasic synovial sarcoma of the lung stressing the histologic and immunohistochemical characteristics, genetics and differential diagnosis. Results: a biphasic pattern and SYT-SSX translocation were demostrated. Comments: histology and immuno-histochemistry lead to diagnosis most of the times but the typical translocation is definitive.