An unusual case of primary leiomyosarcoma at the left lower posterior chest wall with metastasis to the right lung parenchyme is presented. The patient was a 43-year-old man who was asymptomatic but a slow growing hard mass was noted at the left lower posterior chest wall. The chest computed tomography showed a tumor at the left lower posterior chest wall with multiple metastasis to the right lung. The left lower posterior chest wall mass was examined by percutaneous needle aspiration and it was revealed as rhabdomyosarcoma histologically. En bloc resection to the left lower posterior chest wall tumor and metastasectomy to the multiple nodules in the right lung were done and pathological examination finally revealed primary leiomyosarcoma at the left lower posterior chest wall with multiple metastasis to the right lung. Chemotherapy was scheduled as adjunctive measure.