Purpose: To analyze the influence of urethral mobility and Valsalva leak point pressure on postoperative outcomes of transobturator sling (TOT) for female stress urinary incontinence. Materials and Methods: A prospective cohort was conducted including 66 patients submitted to TOT from March 2006 to May 2009. Urethral hypermobility was defined as mobility ≥ 30º on Q-tip test, and Valsalva leak point pressure (VLPP) was classified as greater than 60 cmH 2 O or 60 and less on preoperative urodynamics. These parameters were compared through well defined postoperative objective and subjective success criteria. Intensity of urinary leakage and quality of life was analysed by ICIQ-SF. Statistical analysis was accomplished and the results rendered significant if p < 0.05. Results: Mean follow up was 10 months (3 to 28). Mean age was 55 years (33 to 80), 70% were white and 30% African descendent, mean body mass index was 27 (21 to 38), average vaginal and abdominal deliveries were 2.8 and 0.5 respectively. A quarter had prior stress incontinence surgery. Patients with urethral hypermobility had higher objective success rates (98% versus 81.25%, p = 0.04). The subjective success rate was also greater in the hypermobility group (84% versus 62.5%), but statistical significance was not reached (p = 0.07). VLPP had no influence on either objective or subjective postoperative success rates (p = 0.17 and 0.34, respectively). In the subgroup analysis, those with low mobility and high VLPP had worse objective success rates in comparison to the group with hypermobility and low VLPP (p = 0.04) and also in relation to the remaining of the studied population. Other possible prognostic factors (previous surgery, mixed incontinence, gestational status) had no influence on success rates. Conclusions: High urethral mobility, regardless of the sphincteric status indicated by VLPP, is a favorable prognostic factor for tension-free transobturator tape procedure. No relationship was demonstrated between postoperative success rates and VLPP