The prevalence of urinary incontinence and storage symptoms are known to increase with age, with rates in postmenopausal women as high as 38%.1,2 The bladder trigone, urethra and pelvic floor muscles display estrogen receptors similar to vaginal tissue.3 As such, it has long been suspected that decreases in circulating female sex hormones may play an important role in the etiology of lower urinary tract symptoms such as overactive bladder and stress urinary incontinence in postmenopausal women, which are analogous to symptoms seen with postmenopausal vaginal atrophy. In general, the level of evidence required to recommend an intervention for a specific condition must be balanced with the potential for the intervention to cause adverse effects. In the case of hormone replacement therapy (HRT) in postmenopausal women, it has been well established that there are significant potential adverse effects, including an increased risk of thromboembolic events,4,5 cardiac events,4 breast cancer,5,6 endometrial hyperplasia7 and endometrial cancer.8 Because of these significant risks associated with HRT, the level of evidence required to recommend its use for any condition, including overactive bladder or stress urinary incontinence, must be high. At present, there is no consistent, high-level evidence to support the use of HRT for overactive bladder or stress urinary incontinence.