: This study aimed to evaluate the effectiveness of using indocyanine green (ICG) for assessing ureteral vascularity to reduce ureteral complications in patients undergoing extended hysterectomy for deep endometriosis or oncological indications. : A retrospective-prospective cohort study was conducted at the Centre of Gynecology in Opole, Poland, involving 555 patients who underwent hysterectomy from 2020 to 2023. Patients were categorized based on the Querleu-Morrow classification. ICG was used intraoperatively for vascular assessment in patients with deep endometriosis undergoing wide ureter dissection typical of Type C hysterectomy. : Ureteral complications occurred in 12 (2.2%) patients, with a significantly lower complication rate in those who underwent ICG testing (1.7%) compared to those who did not (22.7%, = 0.001). Prophylactic double-J stenting further reduced the risk of complications. : The use of ICG for intraoperative assessment of ureteral vascularity significantly reduces the risk of ureteral complications in complex hysterectomies. Further studies are needed to confirm these findings.