Objective: This study compared 3 surgical methods of prophylaxis against enterocele formation employed at the time of vaginal hysterectomy. Study Design: One hundred consecutive women undergoing total vaginal hysterectomy for various reasons were randomly assigned to have 1 of 3 surgical methods applied to the posterior superior aspect of the vagina for prophylaxis against enterocele formation. The first procedure involved closing the cul-de-sac and bringing the uterosacral-cardinal complex together in the midline in a vaginal Moschcowitz-type operation. The second procedure was a McCall-type culdeplasty to obliterate the cul-de-sac, plicate the uterosacral-cardinal complex, and elevate any redundant posterior vaginal apex. The third technique used only the peritoneum to close the cul-de-sac, allowing passive movement of the uterosacral-cardinal complex to the midline, no obliteration per se, and no elevation of the posterior vagina. Postoperative findings on pelvic examination were evaluated at 6 weeks, 3 months, and 1, 2, and 3 years. Statistical analysis was performed with the χ² test of independence. Results: At 6 weeks’ follow-up and at 3 months’ follow-up there were no prolapses involving the posterior superior segment of the vagina. At 1 year of follow-up 11 patients had stage 1 or 2 posterior superior segment prolapse. At 2 years’ follow-up this number was 16. At 3 years’ follow-up the McCall-type method was statistically better (χ² = 11.27 with 2 degrees of freedom, P = .004) than the other 2 in preventing postoperative enterocele (n = 2 of 32 with McCall-type procedure, n = 10 of 33 with vaginal Moschcowitz-type procedure, and n = 13 of 33 with peritoneal closure only). Conclusion: When applied at the time of vaginal hysterectomy the McCall-type culdeplasty is superior to a vaginal Moschcowitz-type procedure and to simple peritoneal closure in preventing subsequent enterocele. (Am J Obstet Gynecol 1999;180:859-65.)