Trabectedin is an alkylating agent registered in Europe for the treatment of advanced metastatic soft-tissue sarcomas, whose activity has been documented mainly in liposarcomas or leiomyosarcomas. Here, we report the response achieved in a patient with lung metastases from synovial sarcoma. A man with a large synovial sarcoma of the axilla underwent three cycles of neoadjuvant epirubicin+ifosfamide before complete excision, followed by three additional cycles of chemotherapy and radiotherapy. After 14 months, bilateral lung metastases appeared and were first treated with a prolonged 14-day continuous infusion of high-dose ifosfamide without response, and then with second-line trabectedin. A partial radiological response was achieved; dosage was reduced to 1.1 mg/m because of mild asthenia, grade 3 neutropenia, grade 3 nausea and vomiting, and reversible transaminase elevation. After 9 months of treatment, the lung nodules progressed, the patient received sorafenib, but further progressed and died 19 months after the first appearance of lung metastases. Trabectedin was the only drug that led to a radiological response in this patient with synovial sarcoma, despite being administered at 75% of the standard dose because of dose-limiting nausea and vomiting, in line with more recent data demonstrating activity in translocated sarcomas. We believe that trabectedin represents an attractive option for the treatment of metastatic synovial sarcoma and further clinical studies are warranted.