OBJECTIVE: To compare the efficacy of a single-incision mini-sling, placed in the "U" position, with tension-free vaginal tape (TVT) in the treatment of stress urinary incontinence. METHODS: Women with urodynamic stress incontinence with or without genital prolapse were randomized to receive a mini-sling or TVT (N=263). Those randomized to the mini-sling received two "sham" suprapubic incisions to facilitate blinding. The primary outcome was subjective cure (absence of any urinary incontinence or retreatment) as assessed at 1 year. This trial was a noninferiority study design. RESULTS: Participants receiving the mini-sling were less likely to have a bladder injury (0.8% compared with 4.8%; P=.0.46), more likely to be discharged without a catheter (78.5% compared with 63%; P=.008), and had less pain for postoperative days 1-3. One year after surgery, the rate of cure was similar between treatment groups (mini-sling 55.8% compared with TVT 60.6%; mean difference, 4.8%; 95% confidence interval, -16.7 to +7.2); however, this did not meet our predefined noninferiority criteria of -12%. Incontinence severity at 1 year was greater with the mini-sling than with TVT (mean severity score ± SD: 2.2±2.7 compared with 1.5±1.9; P=.015), resulting predominantly from a higher proportion of participants with "severe" incontinence postoperatively (16% compared with 5%; P=.025). CONCLUSION: The mini-sling placed in the "U" position results in similar subjective cure rates to TVT 1 year after surgery but postoperative incontinence severity is greater with the mini-sling than with TVT. LEVEL OF EVIDENCE: I.