The Authors report a case of extraskeletal Ewing's sarcoma of thoracic wall in a 15-year-old sport-man, who complained about pain in the left upper extremity. The diagnosis was performed by radiology (ultrasound study, TC, RM) and pre-operative needle-aspiration biopsy. The patient was treated by neoadjuvant chemotherapy, wide surgical resection and, then, radiotherapy. Neither local recurrence nor metastases have developed for 8 months.