A 68-year-old woman was admitted to our hospital with a left anterior chest wall tumor. A percutaneous needle biopsy was performed, leading to a pathological diagnosis of pleomorphic rhabdomyosarcoma. A wide en bloc excision of the left anterior chest wall was performed, including the left sixth and seventh ribs. The defect of the chest wall was closed with Marlex mesh. Postoperative adjuvant chemotherapy (CYVADIC) was administered. The patient remained free of local recurrence two years after surgery. We conclude that wide en block excision and close follow-up are important in the management of rhabdomyosarcoma of the chest wall because of a high risk of recurrence.