Background: Routine drainage after partial hepatic resection has long been controversial. Methods: Three hundred and twenty-eight patients who underwent hepatic resections for liver tumors without biliary-enteric and gastrointestinal anastomoses were analyzed using propensity score matching analysis with respect to if and when a prophylactic drain was used and for how long. The criteria for drain placement were established and validated. Results: Our criteria for drain placement were chosen according to postoperative percutaneous abdominal drainage risk factors, organ/space surgical site infections (SSIs), hepatic resection method, intraoperative bile leakage and operative time (≥300 min). The organ/space SSI rate was significantly lower in the group in which abdominal drain removal occurred 2 days after surgery. We decided to remove the abdominal drains on postoperative day 2 when the drain-fluid bilirubin concentration was less than 3 times the serum bilirubin concentration. After our criteria for drain management were developed in 2011, the number of inserted drains, postoperative percutaneous abdominal drainages, postoperative complications, SSI rates and postoperative hospital stays were significantly lower. Conclusions: Our criteria for abdominal drain management facilitate favorable postoperative outcomes.