We evaluated risk factors for prolonged pleural effusion after surgery in 35 children who underwent total cavopulmonary connection (TCPC). Duration of their chest tube drainage was 5.4±7.0 days (1-41, median 3). In univariate analysis, significant risk factors for prolonged pleural drainage over 7 days were preoperative body weight (p=0.03), preoperative cardiothoracic ratio (p=0.03), cardiopulmonary bypass (CPB) time (p=0.02), homologous blood transfusion (p=0.03), serum protein concentration at CPB weaning (p=0.04), central venous pressure (CVP) averaged during 3 postoperative days (p=0.01) and body weight change during 3 postoperative days (p=0.01). However multivariate analysis showed only CVP averaged during 3 postoperative days was a significant risk factor for prolonged chest tube drainage (p=0.03, odd's ratio 3.3). In conclusion, to keep the central venous pressure as low as possible during the early postoperative period might decrease the duration of pleural drainage.