In a 12-month period from October 1994 to September 1996, over 350 hospitals in England, Wales, Northern Ireland, the Channel Islands, and the Isle of Man participated in an investigation of major operative and postoperative complications associated with hysterectomy for benign causes. The staff at participating hospitals collected information for all such hysterectomies performed during this 12-month period by completing questionnaires at 3 points in the management of the patient. The first was at the time of surgery, the second at discharge, and the third 6 weeks after surgery. There were a total of 37,295 qualifying procedures performed during the study period. Information from the sixth-week postoperative visit was available for 26,973 (72%) cases. The average age of patients undergoing hysterectomy was 45 years. The most common indication for surgery was dysfunctional uterine bleeding (46%), followed by fibroids (19%) and prolapse (19%). Other indications included endometriosis and adenomyosis (5%) and pelvic mass (3%). Over half (58%) of the procedures were performed by consulting-level surgeons who also served as supervisors in 34% of the cases carried out by nonconsultants. Two thirds of the cases (24,772; 67%) were total abdominal hysterectomy (TAH), 30% (11,122) were vaginal hysterectomy (VAH), and 3% (1154) were laparoscopically assisted vaginal hysterectomy (LAVH). There were 14 deaths in this study (mortality rate 0.38 per 1000). Eight women died before discharge and 6 died within 6 weeks after surgery. No patient died during surgery and no deaths were among the women who had LAVH. There were a total of 1295 (3.5%) major operative complications and 383 (1%) postoperative complications. The number of complications tended to decrease with increasing age of the patient (11% decrease in odds of complications for each 10 years of age; P ϭ 0.002). The risk of operative complications increased with increasing parity (odds ratio, 1.04; 95% confidence interval, 1.01-1.08 for each pregnancy). Operative and postoperative complications were most common in LAVH procedures (6.1% and 1.7%, respectively), with comparable rates of 3.1% and 0.9% in TAH and 3.1% and 1.2% in VAH (P Ͻ0.001 and P ϭ 0.15, respectively). Hysterectomies being performed to remove fibroids had the highest risks of complications (operative 4.4% and postoperative complications 1.2%). Other indications carried risk of 3.6% and 1.0% for dysfunctional uterine bleeding, 2.7% and 1.1% for prolapse, 3.1% and 0.8% for endometriosis/adenomyosis, and 3.7% and 0.8% for pelvic mass. The risk of operative and postoperative complications was higher in women with a history of serious illness (4.8% and 1.5%) compared with no such history (3.4% and 1.0%, P Ͻ0.001 and P ϭ 0.024, respectively). Serious illness was also associated with higher risk of operative complications in women undergoing hysterectomy for fibroids. No significant differences in rates of operative or postoperative complications were seen according to the operator or presence of a supervisor. T...