Background and Aims The incidence of liver cancer is on the rise worldwide, which seriously affects human health. Hepatectomy is usually the first choice for the treatment of liver cancer, but its incidence of postoperative complications remains high and long-term efficacy needs to be improved. Pleural effusion is a common complication after hepatectomy. Studies have found that serum albumin level, alcohol consumption, right liver resection and other factors are closely related to the occurrence of pleural effusion after hepatectomy, but there is no unified conclusion at present. This study was conducted to investigate the risk factors for pleural effusion in patients with liver cancer after hepatectomy by means of Meta analysis, so as to provide a framework for reducing the incidence of pleural effusion after hepatectomy.Methods The studies concerning the influencing factors for pleural effusion in patients with liver cancer after hepatectomy published from the inception of databases to October 2020 were searched in several national and international databases. The literature was screened according to the inclusion and exclusion criteria, and the data extraction table was developed. Meta-analysis of each variable was performed using RevMan 5.3 software.Results A total of 13 case-control studies were included, involving 5 422 patients. Results of Meta-analysis showed that the main risk factors for pleural effusion after hepatectomy in patients with liver cancer included advanced age (MD=5.03, 95% CI=1.85-8.21), low serum albumin before surgery (OR=-1.28, 95% CI=-2.14-0.42), history of alcohol consumption (OR=1.46, 95% CI=1.03-2.06), concomitant chronic obstructive pulmonary disease (OR=3.15, 95% CI=1.15-8.59), hepatitis B virus and hepatitis C virus infection (OR=0.98, 95% CI=0.72-1.34; OR=2.17, 95% CI=1.18-4.00), ascites (MD=7.13, 95% CI=3.53-14.40), large tumor diameter (MD=1.30, 95% CI=0.27-2.33), prolonged hilar occlusion (MD=3.24, 95% CI=1.65-4.83), large intraoperative blood loss (MD=482.99, 95% CI=183.24-782.74), long operative time (MD=67.14, 95% CI=47.49-86.79), right liver tumor resection (MD=10.29, 95% CI=4.60-22.99), high postoperative total bilirubin (TBIL) level (MD=19.83, 95% CI=6.17-33.49), long prothrombin time after operation (MD=2.15, 95% CI=0.19-4.10), and low postoperative albumin (MD=-4.06, 95% CI=-7.07-1.06). The uncertain factors included preoperative TBIL, cirrhosis, and diabetes mellitus.Conclusion A total of 14 risk factors for pleural effusion after hepatectomy are identified in this study, and corresponding preventive measures against these risk factors are helpful for reducing the occurrence of pleural effusion after hepatectomy. The conclusion still needs to be verified by larger sample size and more rigorous multicenter randomized controlled trials in the future.