Anti-Müllerian hormone (AMH), a quantitative marker of ovarian reserve, is used for both clinical and research purposes in the field of reproductive medicine. Numerous AMH assays have been developed. Among other factors, the lack of large-scale comparisons of the various assays hinders the universal interpretation of AMH levels. Moreover, little is known of the practical performance of highly sensitive assays compared with conventional assays with regard to the very low AMH levels found in women nearing menopause. This study aimed to compare the measurements of the Gen II (Beckman Coulter) assay with those of the highly sensitive picoAMH (AnshLabs) assay.