OBJECTIVE: To compare efficacy and safety of trocar-guided tension-free vaginal mesh insertion with conventional vaginal prolapse repair in patients with recurrent pelvic organ prolapse. METHODS: Patients with recurrent pelvic organ prolapse stage II or higher were randomly assigned to either conventional vaginal prolapse surgery or polypropylene mesh insertion. Primary outcome was anatomic failure (pelvic organ prolapse stage II or higher) in the treated vaginal compartments. Secondary outcomes were subjective improvement, effects on bother, quality of life, and adverse events. Questionnaires such as the Incontinence Impact Questionnaire and Urogenital Distress Inventory were administered at baseline, 6 months, and 12 months. Anatomic outcomes were assessed by an unblinded surgeon. Power calculation with alpha=0.05 and beta=0.80 indicated that 194 patients were needed. RESULTS: Ninety-seven women underwent conventional repair and 93 mesh repair. The follow-up rate after 12 months was 186 of 190 patients (98%). Twelve months postsurgery, anatomic failure in the treated compartment was observed in 38 of 84 patients (45.2%) in the conventional group and in eight of 83 patients (9.6%) in the mesh group (P<.001; odds ratio, 7.7; 95% confidence interval, 3.3-18). Patients in either group reported less bulge and overactive bladder symptoms. Subjective improvement was reported by 64 of 80 patients (80%) in the conventional group compared with 63 of 78 patients (81%) in the mesh group. Mesh exposure was detected in 14 of 83 patients (16.9%). CONCLUSION: At 12 months, the number of anatomic failures observed after tension-free vaginal mesh insertion was less than after conventional vaginal prolapse repair. Symptom decrease and improvement of quality of life were equal in both groups. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00372190. LEVEL OF EVIDENCE: I.