Objective: To determine the incidence and predictors of risk for operative complications, conversions to laparotomy, and postoperative admissions after laparoscopic procedures. Methods: We obtained demographic information on and medical histories of a consecutive series of 843 women who underwent laparoscopic surgery for all procedures other than tubal ligation at Brigham and Women's Hospital during 1994. All major complications after surgery were recorded. Major operative complications were defined as bowel, bladder, ureter, or vascular injuries or significant abdominal wall or other internal bleeding. Categorical analysis was used to compare differences in the rates of operative complications, conversions to laparotomy, and postoperative admissions after laparoscopy. We also estimated the influence of medical history and specific laparoscopic procedures on the risk of adverse complications after surgery. Results: Operative complications and conversion to laparotomy occurred in 1.9% and 4.7% of laparoscopic procedures, respectively. Complications included four bowel, two bladder, one ureteral, two vascular, and five abdominal wall injuries. There were 165 patients (19.6%) admitted postoperatively. Aside from the type of operative procedure, increasing age was the most important predictor of complications. Relative to all other operative procedures, women treated for endometriosis or ovarian cystectomy had generally low rates of operative complications, conversions to laparotomy, and postoperative admissions. In contrast, 12.5% of women undergoing laparoscopically assisted vaginal hysterectomy experienced operative injuries or abdominal bleeding and 90% were hospitalized postoperatively. Conclusion: Serious operative complications after gynecologic laparoscopy were rare in this patient population. The more complex laparoscopic procedures resulted in proportionately greater rates of operative complications, conversions to laparotomy, and postoperative admissions to the hospital.