OBJECTIVE: To identify risk factors for urologic reconstruction during surgery for endometriosis. PATIENTS AND METHODS: We retrospectively identified patients in a surgical pathology database undergoing surgery for endometriosis at our institution from 2010 to 2015 and subsequently identified those patients with ureteral involvement. Patients were categorized as requiring minimal urologic surgery (eg, ureterolysis only) or more extensive urologic surgery (eg, ureteral reimplant). All patients were undergoing surgery for endometriosis, and preoperative risk factors were then identified to predict the need for intraoperative extensive urologic surgery. RESULTS: Of 386 women undergoing surgery for endometriosis, 82 (21%) women required a surgical procedure on the ureter. Fifteen of these 82 patients (18.3%) with ureteral involvement required urologic surgical expertise in the form of either ureteral reimplantation with or without psoas hitch, or ureterolysis with ureteral stenting or omental wrap. The remaining 67 underwent ureterolysis alone or no intervention. The presence of flank pain, any urinary symptom, or hydronephrosis on preoperative imaging was a significant predictor of the need for major urologic intervention. CONCLUSION: In patients with endometriosis undergoing surgery who complain of flank pain, any urinary symptom, or have hydronephrosis on preoperative imaging, one should have a high suspicion for needing to perform urologic reconstruction during surgery. Planning for this additional operation can afford the opportunity for appropriate urologic consultation and patient counseling.