Objective: To determine whether concomitant surgeries affected outcomes in a randomized trial comparing retropubic midurethral sling (MUS) vs transobturator MUS. Methods: Subjects (n = 597) were stratified into 4 groups based on type of concomitant surgeries: group I had anterior/apical with or without posterior repairs (n = 79, 13%); group II had posterior repairs or perineorrhaphy only (n = 38, 6%); group III had nonprolapse procedures (n = 34, 6%); and group IV had no concomitant surgeries (n = 446, 75%). Complication rates, voiding dysfunction, objective and subjective surgical failure rates, and changes in urodynamic values (postop minus preop) were assessed and compared in these 4 groups. Results: There were no differences in complications, voiding dysfunction, and subjective failure outcomes between these 4 groups. Group I had lower odds ratio of objective surgical failure compared with group IV (OR 0.38, 95% CI 0.18-0.81, P =.05). The OR of failure of all patients undergoing concomitant surgeries (groups I-III) was lower than group IV (OR 0.57, 95% CI 0.35-0.95, P =.03). The change in Pdet@Qmax (from pressure-flow) was significantly higher in group III vs IV (P =.01). The change in Q max. (from uroflowmetry) was significantly less in groups I and II vs group IV (P =.046 and.04, respectively). Conclusion: Concomitant surgeries did not increase complications. Subjects who underwent certain concomitant surgeries had lower failure rates than those undergoing slings only. These data support safety and efficacy of performing concomitant surgery at the time of MUS. © 2012 Elsevier Inc. All Rights Reserved.