In children with pneumonia, persistent fever and/or elevated inflammatory markers despite adequate antibiotic therapy, pleural empyema should be suspected. The most frequent cause is an infection due to Streptococcus pneumoniae but less often and primarily in young infants due to Staphylococcus aureus. The diagnosis is based on radiological and ultrasound examination of the thorax and biochemical and microbiological analyses of the effusion. In early stages with an uncomplicated effusion, antibiotic therapy with ampicillin and sulbactam is sufficient. With a larger effusion, respiratory distress, persistent fever and/or persistently elevated inflammatory markers, a small diameter drainage tube should be placed and fibrinolytic therapy with urokinase initiated. In the case of failure of these measures surgical therapy, primarily performed as video-assisted thoracoscopy (VATS), is indicated.