A clinical study of cis-platinum was conducted on 5 patients with Ewing's sarcoma. Cis-platinum was preoperatively administered at doses of 70-100 mg/m2. Good response on imaging diagnosis was recorded in all cases. With regard to side effects, 2 of the 5 patients suffered from hearing loss, but only slight bone marrow suppression was observed. We concluded that cis-platinum was effective for the preoperative treatment of Ewing's sarcoma.