Mechanical stability of the urogenital tract depends on intact collagen fibers. Because of difficulties in quantitating collagen, some authors have investigated collagen breakdown by measuring matrix metalloproteinases expression. We biopsied 68 post-menopausal women during operation to evaluate matrix metalloproteinase-1 (MMP-1) expression in uterosacral ligament biopsies from women with pelvic organ prolapse (POP) (n = 34) and controls with normal pelvic support (n = 34). The controls were matched to the POP group by age, body mass index, parity and duration of postmenopausal state. Immunohistochemistry for MMP-1 was performed on formalin fixed and paraffin embedded sections. Women with POP had a significantly higher MMP-1 expression (p = 0.047) which confirms an association, although not a causal relation, between POP and increased MMP-1 expression.