OBJECTIVE: To compare the effects of the levonorgestrel intrauterine system and endometrial ablation in reducing heavy menstrual bleeding. DATA SOURCES: Medline and EMBASE were searched online using Ovid up to January 2009, as well as the reference lists of published articles, to identify randomized controlled trials comparing the levonorgestrel intrauterine system with endometrial ablation in the treatment of heavy menstrual bleeding. METHODS OF STUDY SELECTION: This systematic review and meta-analysis was restricted to randomized controlled trials in which menstrual blood loss was reported using pictorial blood loss assessment chart scores. TABULATION, INTEGRATION, AND RESULTS: Six randomized controlled trials that included 390 women (levonorgestrel intrauterine system, n=196; endometrial ablation, n=194) were retrieved. Three studies pertained to first-generation endometrial ablation (manual hysteroscopy) and three to second-generation endometrial ablation (thermal balloon). Study characteristics and quality were recorded for each study. Data on the effect of treatment on pictorial blood loss assessment chart scores were abstracted, integrated with meta-analysis techniques, and presented as weighted mean differences. Both treatment modalities were associated with similar reductions in menstrual blood loss after 6 months (weighted mean difference, -31.96 pictorial blood loss assessment chart score [95% confidence interval (CI), -65.96 to 2.04]), 12 months (weighted mean difference, 7.45 pictorial blood loss assessment chart score [95% CI, -12.37 to 27.26]), and 24 months (weighted mean difference, -26.70 pictorial blood loss assessment chart score [95% CI, -78.54 to 25.15]). In addition, both treatments were generally associated with similar improvements in quality of life in five studies that reported this as an outcome. No major complications occurred with either treatment modality in these small trials. CONCLUSION: Based on the meta-analysis of six randomized clinical trials, the efficacy of the levonorgestrel intrauterine system in the management of heavy menstrual bleeding appears to have similar therapeutic effects to that of endometrial ablation up to 2 years after treatment.