Objectives: To investigate the potential beneficial effects of posterior pericardial drainage in patients undergoing heart surgery. Methods: Multiple online databases and relevant congress proceedings were screened for randomized controlled trials assessing the efficacy and safety of posterior pericardial drainage, defined as posterior pericardiotomy incision, chest tube to posterior pericardium, or both. Primary endpoint was in-hospital/30 days' cardiac tamponade. Secondary endpoints comprised death or cardiac arrest, early and late pericardial effusion, postoperative atrial fibrillation (POAF), acute kidney injury, pulmonary complications, and length of hospital stay. Results: Nineteen randomized controlled trials that enrolled 3425 patients were included. Posterior pericardial drainage was associated with a significant 90% reduction of the odds of cardiac tamponade compared with the control group: odds ratio (95% confidence interval) 0.13 (0.07-0.25); P < .001. The corresponding event rates were 0.42% versus 4.95%. The odds of early and late pericardial effusion were reduced significantly in the intervention arm: 0.20 (0.11-0.36); P < .001 and 0.05 (0.02-0.10); P < .001, respectively. Posterior pericardial drainage significantly reduced the odds of POAF by 58% (P < .001) and was associated with significantly shortened (by nearly 1 day) overall length of hospital stay (P < .001). Reductions in postoperative complications translated into significantly reduced odds of death or cardiac arrest (P < .03) and numerically lower odds of acute kidney injury (P < .08). Conclusions: Posterior pericardial drainage is safe and simple technique that significantly reduces not only the prevalence of early pericardial effusion and POAF but also late pericardial effusion and cardiac tamponade. These benefits, in turn, translate into improved survival after heart surgery.