The purpose of the present study was to retrospectively investigate the chest radiograph (CR) and CT findings of childhood pneumonia complicated by cavitary necrosis, and to evaluate the role of CT in decision-making for surgical intervention. Chest CT was performed in 51 patients presenting with persistent or progressive pneumonia, respiratory distress and sepsis despite 7-10 days of appropriate antibiotic treatment and closed tube drainage. Chest radiograph and CT findings were retrospectively evaluated in 23 patients (45%) with cavitary necrosis. Chest radiographs showed consolidation in 19 of 23 patients, cavitation in five patients, parapneumonic effusions in 17 patients and air-fluid levels in the pleural space in one patient. The CT scans demonstrated consolidation and cavitary necrosis in all patients. There were parapneumonic effusions in all patients with concomitant loculated collections in six patients. Twenty-two of 23 patients had pleural thickening. In seven patients there were air-fluid levels in the pleural space. In five of these patients, CT scans demonstrated bronchopleural fistulae. On the basis of the CT and clinical findings, 11 patients underwent surgical intervention. Computed tomography is superior to CR for demonstrating cavitary necrosis complicating pneumonia, and other parenchymal and pleural complications. It also has a crucial decision-making role for surgery.