Synovial sarcoma is a rare soft tissue sarcoma that typically arises in the extremities of young adults. We report a case of a 26-year-old pregnant woman with biopsy-proven primary synovial sarcoma of the lung that was treated with chemotherapy with radiographic response. This is only the third documented case of primary pulmonary synovial sarcoma occurring during pregnancy and the first case where chemotherapy was given.