A study was conducted to compare the efficacy and complications of tension-free vaginal tape (TVT), transobturator vaginal tape inside-out TVT-O and transobturator vaginal tape out-inside (TOT) procedures for the surgical treatment of female stress urinary incontinence SUI.This study is a prospective randomized trial involving 187 women with primary SUI; 77 received TVT, 65 received TVT-O, and 45 patients were treated with TVT-O between June 2002 and December 2009. Before the operation, a complete medical history was taken and a gynecologic examination was performed, including subjective symptoms, history and urodynamic studies. Postoperative data included mean operation time, days of hospitalization, postoperative complications and efficacy evaluation. Therapeutic effect was assessed by presence or absence of incontinence when abdominal pressure increased.The history, physical examination and urodynamic studies among the three groups have no significant difference (P>0.05). The total cure rate was 91.4%. The cure rate in TVT, TVT-O and TOT groups were 90.9%, 92.3% and 91.1%, respectively. There was no significant difference (P>0.05). Mean operative time showed no significant difference between TVT-O and TOT groups, but both were significantly shorter than TVT group (26.90±16.80, 20.00±13.50 vs 48.20±21.90). The mean postoperative hospital stay showed no significant difference between TVT and TVT-O groups, but both groups were significantly longer than TOT group. Mean postoperative hospital stay of TVT, TVT-O and TOT were 5.00±2.40 days, 4.00±2.20 days and 2.30±0.80 days, respectively. The complication rate in TVT, TVT-O and TOT groups was 15.60%, 9.20% and 8.90%, respectively. In TVT group, 4 patients experienced bladder perforation, postoperative dysuria or retention occurred in 7 cases and was cured by urethral dilation, hematomas of retropubic space in 1 patient. No bladder injury occurred in TVT-O and TOT group, 3 patients had postoperative dysuria or retention and 3 patients had transient dysfunction of both lower limbs postoperatively in TVT-O group, 2 patients had postoperative dysuria or retention and 2 patients had transient dysfunction of both lower limbs postoperatively in TOT group.The three tension-free urethral suspension techniques have similar efficacy, all of them are safe and effective procedures for the treatment of female SUI. Compared with TVT, TVT-O and TOT are simpler, less invasive and have fewer complications.