OBJECTIVE:: To compare efficacy of transobturator tape with tension-free vaginal tape (TVT) in the treatment of stress urinary incontinence in women with intrinsic sphincter deficiency. METHODS:: One hundred sixty-four women diagnosed with urodynamic stress incontinence and intrinsic sphincter deficiency with or without concomitant pelvic organ prolapse repair were randomized to receive TVT or transobturator tape. The primary outcome was the presence or absence of urodynamic stress incontinence at 6 months postoperatively. Secondary outcomes were the rate of operative complications, symptomatic stress incontinence requiring further surgery, and quality-of-life questionnaires. RESULTS:: Of 180 women eligible to participate, 164 were enrolled and underwent surgery. Of the 138 patients assessed at 6 months with urodynamic studies, 14 of 67 (21 ) had urodynamic stress incontinence in the TVT group compared with 32 of 71 (45 ) in the transobturator tape group (P=.004), with nine women in the transobturator tape group having repeat sling surgery compared with none in the TVT group. In the intention-to-treat analysis, the incident rate difference for request of repeat surgery was 9.7 (95 confidence interval [CI] 0-19.9); repeat surgery would be requested in one of every six transobturator tape procedures compared with 1 of every 16 TVT procedures. The risk ratio of repeat surgery was 2.6 (95 CI 0.9-9.3) times higher in the transobturator tape group. CONCLUSION:: Retropubic TVT is a more effective operation than the transobturator tape sling in women with urodynamic stress incontinence and intrinsic sphincter deficiency.