Background: The routine use of abdominal drains after hepatic resection is a matter of debate as well as its long-term maintenance. However, undetected bile leakage may be the source of major morbidity, which may require interventional procedures or even reoperations. The aim of this study was to investigate the safety and effectiveness of the systematic long-term drains maintenance after hepatic resection for liver tumors. Methods: We reviewed the records of 327 consecutive patients who underwent hepatic resection at our Unit based on the same prospective selection process. One-hundred-sixty-eight patients (52%) had hepatocellular carcinoma, 105 (32%) had colorectal liver metastases, and 54 (16%) had other malignancies. Each patient had abdominal drains placement, and those drains were maintained for at least 7 days after surgery. The bilirubin concentration was systematically sampled in the drain in 3rd, 5th, and 7th postoperative day (POD).Results: The median number of drains per patient was 2 (range 1-5). The 90-days mortality was 1%. The overall morbidity rate was 17% and major morbidity occurred in 6%. The trend of the bilirubin concentration showed that the bilirubin significantly increased between the 3rd and the 5th POD (P<0.001), and then significantly decreased at the 7th POD (P<0.001). Eight patients (2%) had biliary fistula, which was conservatively treated by drain maintenance. Only one patient (0.3%) required a percutaneous drainage for a fluid collection developed after drains removal. No infections or others drains-related complications occurred.Conclusions: The late onset of biliary fistula justify the long-term maintenance of drains after hepatic resection for liver tumors, which is a safe and effective method in reducing the rate of undetected abdominal collections and in preventing postoperative morbidity and mortality.