Background: We aim to assess the long-term efficacy of transvaginal high uterosacral ligament suspension (HUS) procedure for middle compartment defect-based pelvic organ prolapse (POP).Methods: We performed a retrospective review of 84 women with middle-compartment defect-based POP who underwent transvaginal HUS as the primary surgical treatment without mesh augmentation from January 2007 to January 2019. All 84 patients manifested ≥ grade-II middle-compartment defectbased POP. Follow-up visits were performed 2, 6 and 12 months after surgery and then annually, including questionnaires and clinical examination using pelvic organ prolapse quantitation system (POP-Q). Surgical success required to fulfill all three of these criteria: (I) anterior or posterior vaginal wall prolapsed the leading edge of 0 cm or less and apex of 1/2 total vaginal length or less; (II) the absence of POP symptoms as reported on the PFDI-20 question No. 3 ("do you usually have a bulge or something falling out that you can see or feel in your vaginal area?"); and (III) no prolapse re-operations or pessary use during the study period.Results: Of 84 women, 56 cases (66.7%, 56/84) were evaluated at a ≥5-year follow-up. The 5-year recurrence rates for patients with prolapse of either the anterior vaginal wall, vaginal vault, or posterior vaginal wall, or prolapses in multiple sites, were 7.1% (4/56), 0, 1.8% (1/56), and 3.6% (2/56), respectively.The surgery success rate was 87.5% (49/56). None of the recurrent women underwent retreatment. The satisfaction rate was 91.1% (51/56).Conclusions: Transvaginal HUS without mesh augmentation is a safe and effective procedure in the surgical treatment of patients with middle-compartment defects. Anatomical, functional, and subjective outcomes were very satisfactory.