Importance: The comparison between single-incision slings (SISs) and midurethral slings has been documented in the literature, but results vary according to the SIS device., Objectives: The purpose of this study is to assess whether SIS (Solyx) is noninferior to transobturator (TOT) (Obtryx) sling for treating women with confirmed stress-predominant urinary incontinence., Study Design: A prospective, parallel, nonblinded, multicenter, noninferiority, randomized controlled study with 114 patients were randomized and followed 6 and 12 months after surgery. Interventions were midurethral TOT sling (Obtryx-halo; n = 58) or SIS (Solyx; n = 56). The primary outcome was improvement in the Patient Global Impression of Improvement (PGI-I). Secondary outcomes were the Kings Health Questionnaire (KHQ) instruments after treatment, subjective improvement, and surgical outcomes., Results: Both groups were homogeneous ( P = NS) regarding sociodemographic and clinical variables. There was improvement in the PGI-I after 6 ( P = 0.001) and 12 months ( P = 0.001) of treatment for women who underwent TOT sling. After 6 months, KHQ scores improved in the TOT group for the following domains: role limitations ( P = 0.026) and physical limitations ( P = 0.006). After 12 months, the TOT group presented better KHQ scores that were statistically significant from the SIS group in incontinence impact ( P = 0.012), physical limitations ( P = 0.001), and severity measures ( P = 0.017). Moreover, the TOT group presented higher subjective improvement after 6 months ( P = 0.006) than the SIS group. Mesh erosion was higher in the SIS group ( P = 0.006). Reoperations were not statistically different between groups., Conclusion: There were higher scores in the PGI-I score and higher subjective improvement for the TOT sling after 6 and 12 months of treatment when compared with the SIS group., Competing Interests: The authors have no conflict of interest to disclose, except for Luiz Gustavo Brito, who received a donation from Boston Scientific regarding the slings and minislings. However, the company had no influence on the protocol and manuscript writing or at any phase of the study development., (Copyright © 2023 American Urogynecologic Society. All rights reserved.)