Pelvic floor connective tissue degeneration is closely associated with retrogradation of its dominating nerve fibers. We hypothesized that some neuropeptides from pelvic floor tissue might be involved in the pathological progress of stress urinary incontinence (SUI) and pelvic organ prolapse (POP) in women. Thirty premenopausal and 31 postmenopausal patients participated in the study. The morphological appearance in the vaginal tissue was examined. The vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide-38 (PACAP) immunoreactivities (ir-VIP, ir-PACAP) were tested by immunohistochemistry and radioimmunoassay. We found that the VIP and PACAP immunostainings were weaker and sparser, and ir-VIP and ir-PACAP levels were significantly decreased in the anterior vaginal wall in the premenopausal and postmenopausal SUI or POP patients. Ir-VIP and ir-PACAP levels were reversely correlated with the age and menopausal status in the SUI or POP patients. Our data suggest that VIP and PACAP may participate in the pathophysiological process of SUI and POP.