Pleural effusions after modified Fontan operations are unpredictable and contribute significantly to the morbidity and prolonged hospitalization. Chemical pleurodesis is widely performed in adults for malignant pleural effusions, but has found less chance of usage for benign cases or the cases with unidentified etiology. Although it is a safe and easily performed procedure, the use of bleomycin for the treatment of pleural effusions in the pediatric age population has been rarely reported in the literature. In this manuscript, we present a case with prolonged pleural effusion after extracardiac Fontan operation, which was successfully treated with bleomycin pleurodesis.