Pneumoblastoma is a rare pulmonary malignant tumor, demonstrating atypical histological features analogous with the epithelial and mesenchymatous formations associated in the embryonic lung. Their dysembryoplastic origin, suggested initially because of these appearances, is currently contested in favor of a neoplastic origin. They are rare tumors, but they still stimulate interest because of certain particular features related to their course, and because of the problem of their histogenesis.