Study Objective: To compare the safety, efficacy, and adverse events of the new mini-adjustable sling system “I-stop-mini” with transobturator midurethral slings “Obtryx” (Boston Scientific, Marlborough, MA) in women with stress urinary incontinence. Design: A single-center, retrospective cohort study. Setting: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taiwan. Patients: A total of 347 patients who underwent I-stop-mini or Obtryx for stress urinary incontinence treatment. Interventions: Midurethral sling with either I-stop-mini or Obtryx. Measurements and Main Results: The primary outcomes were objective success and subjective cure rates between the 2 groups. Objective success was evaluated using a 1-hour pad test, and subjective cure was evaluated using a questionnaire score (Incontinence Impact Questionnaire, Urinary Distress Inventory, and International Consultation on Incontinence Questionnaire Short Form). Secondary outcomes were the evaluation of surgical outcomes, operative data, and adverse events between the 2 groups. In total, 171 of 200 I-stop-mini subjects and 127 of 147 Obtryx subjects completed 12 months of follow-up. Regarding the objective success between the I-stop-mini group and the Obtryx group, 1-month postoperative (3.6 ± 5.2 vs 3.9 ± 12.6; p = .765), 6-month postoperative (3.9 ± 5.1 vs 4.2 ± 12.6; p = .848), and 12-month postoperative (4.6 ± 5.6 vs 4.5 ± 13.6; p = .980) 1-hour pad tests showed no significant difference. The 12-month subjective cure rates decreased from 94.7% (1-month postoperative) to 91.2% (12-month postoperative) in the I-stop-mini group and 95.2% (1-month postoperative) to 85.0% (12-month postoperative) in the Obtryx group. Similar and durable efficacy was observed between the 2 groups. The I-stop-mini group had shorter operative times and hospital stays than the Obtryx group; however, both groups showed similar adverse event rates. Conclusion: The objective success and subjective cure rates of I-stop-mini did not differ to those of Obtryx. However, long-term data and further prospective studies on I-stop-mini are necessary to arrive at a definite conclusion.