OBJECTIVES: With the recent updates of clinical guidelines of the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO), aromatase inhibitors have been included in the management of early-stage breast cancer. There has been a great interest to understand the cost-effectiveness of this new alternative therapy which is becoming an “optimal therapy” for breast cancer. The objective of this study is to review the cost-utility studies on aromatase inhibitors for the treatment of early-stage breast cancer and compare reported incremental cost-effectiveness ratios (ICERs). METHODS: We conducted a literature for cost-utility studies on anastrazole, letrozole and exemestane. We reviewed the papers to extract the information on intervention, comparator, ICER, country, perspective, time horizon and clinical data used. For the comparison of reported ICERs, we converted all currencies to US dollars by exchange rate for the cost-year used, then inflated the values to 2008. RESULTS: A total of 20 papers were identified (8 on anastrazole, 8 on letrozole and 4 on exemestane). All studies were from healthcare perspective and sponsored by manufacturers. The time horizon modeled ranged from 7.5 years to lifetime, however majority of the studies modeled lifetime. The studies were from EU countries and North America such as US, Canada, Belgium, Italy, Sweden and UK. The mean ICER values were $24,932 for anastrazole, $21,113 for letrozole and $21,428 for exemestane. CONCLUSIONS: The mean ICERs for all three aromatase inhibitors are below $25,000; hence they appear to be cost-effective compared to tamoxifen therapy for the treatment of early-stage breast cancer.