The authors report a case of pulmonary fibrosarcoma in a newborn. The respiratory distress imposed an urgent thoracotomy at the fifth hour of live. A lobectomy was performed. Three months later a relapse occurred. A second thoracotomy permitted an incomplete resection. The total involution was achieved after 6 months of chemotherapy. Actually no recidive is shown after 20 months of follow up. Its an exceptional case. A unique one was published in 1977.