Rhabdomyolysis is defined as dissolution of striped muscle characterized by leakage of intracellular muscle components into the circulation, which can ultimately lead to renal failure with a possible fatal outcome. This is an uncommon side effect of trabectedin which is used in second-line therapy of metastatic sarcoma after anthracycline and ifosfamide failure. Here, we describe a case of reversible rhabdomyolysis in a male patient with recurrent metastatic synovial sarcoma of the hand, with marked 18F-FDG uptake into his skeletal muscles, after 4 cycles of trabectedin, and who at the same time was taking an alternative medicine (bioflavonoids) suspected of triggering this adverse event.