Urethral sphincter deficiency (USD) is not standardised. Opening vesical pressure could reflect the pressure exerted to overcome urethral resistance during void; thus, we evaluated if it could discriminate USD. Women with urinary symptoms were prospectively assessed with a questionnaire and urodynamics and divided into three groups: urodynamic stress incontinence with USD (group 1), urodynamic stress incontinence related to urethral hypermobility without USD (group 2) and normal urodynamic (group 3). USD was defined as the concomitant presence of severe urodynamic stress incontinence, VLPP <60 cm H2O, MUCP <20 cm H2O and urethral mobility <30 degrees . A total of 145 women were enrolled: 56 in group 1, 50 in group 2 and 39 in group 3. The three groups did not differ for demographics, obstetric and surgical history. The median values for opening vesical pressures were 17.5 (15.6-22.2 95%CI), 30 (27.0-37.3 95%CI) and 30 (30.6-44.2 95% CI) for the groups 1, 2 and 3, respectively. A p value <0.0001 was found when comparing group 1 either with group 2 or 3. Opening vesical pressure is a promising parameter to detect USD.