The uterosacral ligaments are an important part of the pelvic support system and connective tissue alterations are thought to contribute to the development of pelvic organ prolapse (POP). The objective of this study was to compare the expression of matrix metalloproteinases (MMPs) 1 and 2 in these ligaments in women with and without POP. We analyzed the tissue samples obtained from left and/or right uterosacral ligaments of 17 women with POP and 18 controls by immunohistochemistry. There was no difference in MMP-1 expression between women with POP and those without. In contrast, the MMP-2 expression was significantly related to the presence of POP (p=0.004) rather than to age or parity. There was no difference in MMP-1 and MMP-2 expression between left and right uterosacral ligaments in women with POP compared to controls. Our findings strongly indicate that increased MMP-2 expression in uterosacral ligaments is associated with POP.