There have been more than 1000 endometrial laser ablations (ELA) performed at South Cleveland Hospital. The procedure has a high success rate in relieving the symptoms of dysfunctional uterine bleeding (83% sustained improvement over 1-4 years), and there has been no associated major morbidity. To identify factors that are associated with poor outcome, we have reviewed our data on women who progressed to hysterectomy after ELA. Twenty-nine of the first 524 women (5.5%) undergoing ELA have required subsequent hysterectomy. After excluding 3 cases where extensive endometriosis had been diagnosed at concomitant laparoscopy, these women were compared to 26 matched controls who had excellent outcomes. It was observed that young age, dysmenorrhea, and atypical pelvic pain at admission were factors associated with an increased chance of failure. Operative data, including uterine length and treatment times, were similar in both groups, and more than half the poor outcome group had entirely normal uteri. We conclude that good patient selection based on careful history and preoperative examination is of paramount importance in ensuring good treatment outcome.