OBJECTIVE To examine the frequency of ureteral catheter usage, its efficacy in preventing injury, and related complications, because the preoperative routine placement of ureteral catheters as a prophylactic measure to prevent ureteral injury is controversial. METHODS All major gynecologic operations performed between January 1992 and December 1994 were identified. All gynecologic procedures that were preceded by ureteral catheter placement were also identified. A data base maintained by the Department of Quality Management allowed identification of all urinary tract complications and ureteral injuries. Four categories of surgery were analyzed: exploratory laparotomy with catheters, exploratory laparotomy without catheters, operative laparoscopy with catheters, and operative laparoscopy without catheters. The medical records of all patients with urinary tract complications were reviewed. RESULTS Bilateral prophylactic ureteral catheterization was performed in 469 (15.3%) of 3071 patients. A ureteral injury occurred in 4 (0.13%) of 3071 patients. All four ureteral injuries (0.17%) occurred among 2338 patients who underwent exploratory laparotomy. None of the 733 patients who underwent operative laparoscopy suffered ureteral injury. The incidence of ureteral injury in patients who had ureteral catheters placed before exploratory laparotomy was 2 (0.62%) of 322. Two (0.10%) of 2016 patients who did not have prophylactic ureteral catheters suffered a ureteral injury. There was no statistically significant difference in the incidence of ureteral injury between patients who did and patients who did not undergo ureteral catheterization (P=0.094). CONCLUSIONS The use of prophylactic ureteral catheters did not affect the rate of ureteral injury in our patients. The very low incidence of ureteral injury among our patients is attributed mainly to meticulous surgical technique.