OBJECTIVE: It is important to evaluate limb blood flow during the perioperative period to salvage affected limbs in patients with chronic limb-threatening ischaemia (CLTI). However, it is difficult to evaluate limb blood flow during endovascular treatment (EVT). This study aimed to investigate the usefulness of regional tissue oxygen saturation (rSO2) values measured by near-infrared spectroscopy (NIRS) techniques during EVT to predict the wound healing prognosis in patients with CLTI. METHOD: Patients with CLTI who successfully underwent EVT between April 2018 and March 2022 were included. Patients who had infections or failed EVT were excluded. The rSO2 value was measured in the affected limb using the NIRS device (TOE-20, Astem Co., Ltd., Japan) during EVT. At one year after EVT, the patients were divided into two groups: healing and non-healing. Intraprocedural rSO2 values were retrospectively analysed to determine the cut-off value for wound healing using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 34 patients (healing group: 15; non-healing group: 19) were included in this study. Intraprocedural rSO2 values were significantly higher in the healing group than in the non-healing group (51.1±3.4% versus 44.4±5.0%, respectively; p<0.001). ROC curve analysis revealed that the optimal cut-off intraprocedural rSO2 value for wound healing within one year was 47.0% (sensitivity: 86.7%, specificity: 73.7%). CONCLUSION: The results of this study showed that intraprocedural rSO2 values during EVT may be useful in the prediction of postoperative wound healing in patients with CLTI.