Insulin resistance may contribute to the pathogenesis of polycystic ovary syndrome (PCOS). Insulin sensitizing agents have been found to improve insulin resistance and ovulatory dysfunction. Cinnamon extract has been shown to reduce insulin resistance in in vivo and in vitro animal studies by increasing the IRS/PI-3 kinase insulin signaling pathway. We designed this pilot study to test the hypothesis that oral cinnamon extract would improve insulin sensitivity in women with PCOS.