Background <p>No studies exist regarding the methods for evaluating the surgical difficulty of multiple laparoscopic liver resection (MLLR). Hence, this study aimed to evaluate the usefulness of total scores calculated using the IWATE criteria for each resection site to assess the surgical difficulty of MLLR.</p> Methods <p>Medical records of patients who underwent MLLR at Kobe University Hospital between 2010 and 2023 were retrospectively reviewed. First, the total difficulty score was calculated for each patient by summing the IWATE criteria scores for all resection sites. Subsequently, we analyzed the correlation between this total difficulty score and surgical outcomes of MLLR. Finally, receiver operating characteristic analysis was employed to determine the optimal cutoff value of the total difficulty score. This cutoff value was used to categorize patients into the high- and low-total difficulty score groups, allowing for a comparison of their surgical outcomes.</p> Results <p>This study included 63 patients. The total difficulty score correlated with operation time [r = 0.54, 95% confidential interval (CI): 0.34–0.70, <i>P</i> &lt; 0.001] and blood loss (r = 0.27, 95% CI: 0.03–0.90, <i>P</i> = 0.029), and was associated with postoperative complications (odds ratio: 1.33, 95% CI: 1.14–1.60, <i>P</i> &lt; 0.001). Patients with total difficulty scores ≤ 11 and ≥ 12 were included in the low- and high-score groups, respectively. The high-score group exhibited longer operation times (481&#xa0;min vs. 372&#xa0;min, <i>P</i> = 0.001), greater blood loss (110&#xa0;ml vs. 50&#xa0;ml, <i>P</i> = 0.005), and higher overall complication rates (71% vs. 29%, <i>P</i> = 0.001) than the low-score group.</p> Conclusions <p>The total difficulty score based on the IWATE criteria may be a useful tool for assessing surgical difficulty in MLLR.</p> Graphical abstract <p></p>