AimFibrinolytic therapy is commonly used in children with parapneumonic effusion, to facilitate drainage of the effusions and recovery. However, data regarding complications of this treatment in children are limited. We aimed to determine the incidence of pneumothorax (PNX) associated with intrapleural urokinase.MethodsWe analyzed retrospectively collected data of children with parapneumonic effusion who underwent chest drain insertion. The clinical course and complications, including the incidence of PNX, were compared between children who were and were not treated with urokinase.ResultsThe study group included 120 children, of whom 57 were treated with urokinase. Children who were and were not treated with urokinase did not differ in markers of disease severity or in the length of hospitalization. Among the patients treated with urokinase compared to those not treated, the incidence of PNX was higher (35% vs. 6%, p < 0.001) and the median duration of chest drain treatment was longer (6 vs. 4 days, p < 0.001).ConclusionIn our pediatric cohort, intrapleural urokinase was associated with a higher incidence of PNX and did not shorten the duration of hospitalization.