The aim of this study was to determine the interobserver reproducibility of the Halfway Grading System, a scoring system for pelvic organ prolapse. Thirty-six women who underwent abdominal sacroealpopexy were examined by two gynecalogists who were blinded for the medical history and current symptoms of the cooperating women as well as for each other's results. The amount of prolapse of urethra, bladder, cervix, cul de sac, rectum, and perineum was scored on a 5-point scale. The amount of agreement in the judgment of the observers that was expected beyond chance was expressed with a weighted kappa statistic. The overall kappa statistic was 0.59 (95% CI 0.37-0.80). The kappa statistics per anatomic site of greatest prolapse and the site-specific kappa statistics were even lower. The moderate reproducibility of the Halfway Grading System makes it less suitable for clinical care or research. Highly reproducible methods to assess pelvic organ prolapse are warranted.