Receptors for both estrogen and progesterone are present in structures supporting pelvic floor, and therefore, postmenopausal hormone therapy (HT) may affect its function. Traditionally it has been thought that in women estrogen, the principal component of HT, could reduce the risk of common pelvic floor disorders, such as pelvic organ prolapse (POP) and/or stress urinary incontinence (SUI). However, there is limited evidence from larger studies to support the use of systemic or local estrogen treatment for the prevention of these pelvic floor disorders. We have conducted large case-controlled studies in patients with a history of POP or SUI operation and comparing the use of HT to control women without any such operations (matched in regard to age, number of deliveries, and hospital district). Our data indicate that the use of HT increase the risk of both POP and SUI. Furthermore, for SUI the risk appears to increase more the later HT is initiated. In clinical practice women are treated with various HT regimens to treat or prevent pelvic floor disorders. Our data indicate that HT rather increase than decrease risk for POP and/or SUI. Therefore, our findings should be incorporated into patient information for women considering HT use.