PURPOSE OF INVESTIGATION: To compare the efficacy and safety of two different second-generation ablation devices, Novasure impedance control system and microwave endometrial ablation (MEA), in cases of abnormal uterine bleeding (AUB).MATERIALS AND METHODS: This is a randomized controlled trial that took place in a single Gynecological Department of a University Hospital. Sixty-six women with dysfunctional uterine bleeding (DUB), unresponsive to medical treatment, were included in the trial. The ratio of women allocated to bipolar radio-frequency ablation or MEA was 1:1. Follow-up assessments were carried out at three and 12 months post-ablation. The present main outcome measure was amenorrhea rates 12-months post-treatment.RESULTS: The rate of amenorrhea at 12-months post-ablation was significantly higher in women treated by Novasure (25/33; 75.8%) as compared to those treated by MEA (8/33; 24.2%) (rate difference: +51.5%, 95% CI: +27.8 to +67.7).CONCLUSION: In women with DUB, endometrial ablation with Novasure bipolar radiofrequency impedance-controlled system is associated with increased rates of amenorrhea at 12-months post-treatment as compared to the MEA method.