BACKGROUND: Enoxaparin, a low molecular weight heparin, has been used to prevent thrombotic events during major surgery without increasing the rate of hemorrhage. On the other hand, it was reported to cause liver injury, but the details of liver injury induced by prophylactic enoxaparin after abdominal surgery remain unclear. AIMS: This study aimed to clarify the relationship between prophylactic enoxaparin and liver injury after colorectal surgery, and characterize the injury profile. METHODS: We retrospectively reviewed 732 Japanese patients who underwent elective resection of the colorectum, and compared their clinicopathological background, details of surgery, postoperative complications, including liver injury, and the type of liver injury according to prophylactic use of enoxaparin. Univariate and multivariate analyses were performed to identify risk factors for liver injury during the postoperative period. RESULTS: The rate of liver injury was 8.9% for patients treated by prophylactic enoxaparin and 1.4% for those who did not receive enoxaparin after colorectal surgery (p < 0.0001). The median onset of liver injury among patients receiving enoxaparin was seven days, and the majority demonstrated the hepatocellular pattern. Enoxaparin was one of the independent risk factors for postoperative liver injury by multivariate analysis (odds ratio: 7.63, p < 0.0001). CONCLUSIONS: Prophylactic use of enoxaparin markedly increased the rate of postoperative liver injury in patients who underwent colorectal surgery. Our study confirmed that close monitoring of liver function parameters is essential for patients receiving enoxaparin during the postoperative period.