Of the 31 children treated for empyema thoracis secondary to pneumonitis at the Loma Linda University Medical Center, Loma Linda, Calif, from 1980 to 1990, 23 responded to prompt directed antibiotic therapy coupled with drainage, usually tube thoracostomy. All patients were cured clinically; some demonstrated residual pleural reaction with chest roentgenography or computed tomography that resolved over time. Decortication was necessary in eight severely ill children; three required concurrent lung resection for abscess. Distinct from the nonoperated group, there was a pattern of initial antibiotic trials in these patients averaging 6.5 different drugs plus delayed drainage of effusions. Delay in the initiation of antibiotic therapy was six times longer for the operated vs the nonoperated group. Delay to tube thoracostomy was 18 days for the decorticated children compared with 5.4 days for the nondecorticated children. All eight children responded completely and rapidly to their decortications. Roentgenographic changes lagged considerably behind the clinical course of the child, and computed tomographic scans provided better identification of chest tube placement but little information predictive of the need for decortication. Decortication for empyema seldom is necessary when a child is treated promptly with appropriate antibiotics directed by thoracentesis findings, and drainage, usually tube thoracostomy. The criterion for decortication is persistent sepsis, not the roentgenographic appearance of the chest.