OBJECTIVE To determine the influence of surgery on bladder and urethral function by performing a videourodynamic study in female patients with stress urinary incontinence (SUI) before and after a pubovaginal sling procedure. METHODS A total of 14 women with type II SUI, 7 with type III SUI, and 3 with mixed type II/III SUI were included in the study. The pubovaginal sling procedure was carried out using a modified method that minimized interference with the endopelvic fascia. Videourodynamic study was performed before the procedure, within 7 to 14 days postoperatively, and at 3 to 6 months postoperatively. RESULTS Videourodynamic study within 7 to 14 days postoperatively revealed no change in the mean voiding detrusor pressure (Pdet), cystometric capacity, or maximal flow rate (Qmax) compared with the preoperative data. The bladder neck opening time and residual urine amount were significantly increased. Within 3 to 6 months after surgery, Pdet, Qmax, bladder neck opening time, and residual urine amount returned to preoperative levels. An elevation of the bladder neck was noted during coughing in 7 patients. After surgery, de novo detrusor instability was noted in 2 patients (8.3%). No infection or sling failure was noted at a mean follow-up time of 12 months. The success rate was 96%. CONCLUSIONS The pubovaginal sling procedure is an effective method for the treatment of type II or type III SUI. The postoperative videourodynamic results show that this procedure can re-establish a "hammock effect" on the proximal urethra during abdominal straining without compromising urethral resistance.