Background: Postoperative serum ALT levels are one of the most frequently used marker to detect liver tissue damage following liver resection. The aim of this study was to evaluate if minimally invasive liver surgery (MILS) may result in less hepatic injury than open hepatectomy by assessing the differences of postoperative ALT levels. Methods: Patients who underwent MILS between 2009 and 2019 at our unit were included and compared with open liver resections. Median ALT levels was measured on postoperative day (POD) 1, 3 and 5. Postoperative peak transaminase (PPT) of ALT was determined on POD 1. The stabilized inverse probability treatment weighing (SIPTW) process was used to balance the two groups. A multivariable logistic regression analysis was used to analyze factors associated with high PPT. Results: After SIPTW, 292 MILS were compared with 159 open resections. Median ALT levels on POD 1, 3 and 5 were significantly higher in the open group than in the MILS group (301 vs. 187, p = 0.002; 180 vs. 121, p < 0.0001; 104 vs. 60, p < 0.0001; respectively). At the multivariable logistic regression analysis, MILS showed a protective effect for high PPT. Conclusions: MILS was associated with significantly lower postoperative ALT levels compared with open liver resections. MILS showed a protective effect for high PPT.