Primary pulmonary fibrosarcoma is a rare malignant tumor in childhood. In the absence of metastases, complete resection is curative. An 8-year-old boy suffered from unresolving pneumonia due to an obstructing lesion in the left main bronchus. Cytology of the bronchoalveolar lavage fluid and histology of bronchial biopsy revealed the diagnosis of pulmonary fibrosarcoma. The tumor did not respond to chemotherapy, and a total lobectomy with sleeve resection was performed with complete removal of the neoplasm. Two years after the operation the child has no evidence of disease.