Necrotizing pneumonia remains an uncommon complication of pneumonia in children, but its incidence is increasing. Pneumococcal infection is the predominant cause of severe necrotizing pneumonia in children, but methicillin resistant Staphylococcus aureus (MRSA) and Panton-Valentine leukocidin (PVL) staphylococcal infections are also important. We present the case of a four-year-old girl,with an unremarkable medical history, who was admitted in our hospital with a history of high fever, productive cough and tachypnea lasting for 10 days, progressive worsening despite empirical oral antibiotic. Following physical examination, laboratory investigations and thoracic radiography, we established the diagnosis of left lower lobe pneumonia with parapneumonic effusion, acute respiratory failure and sepsis. Medical treatment with systemic antibiotics was initiated, but the evolution was unfavorable. Seriated chest X-rays and also high resolution computed tomography with contrast of the lung were performed, revealing the progression to extensive necrotizing pneumonia with multiple cystic lesions causing right mediastinal deflection. The parenteral broad spectrum antibiotic regimen was adjusted, still with unfavorable evolution, requiring surgical treatment (left inferior lobectomy and pleural draining). Postoperatively, recovery was uneventful. The patient was discharged with clinical and laboratory improvement of his condition, a repeated chest X-ray showing good expansion of upper left parenchyma.