Pre- and postoperative clinical, urodynamic and morphological data from 91 cured and uncured patients with Burch colposuspension and from 54 patients with vaginal repair, were analysed. The results were expected to show possible reasons for the failure of surgery and to demonstrate prognostic criteria for successful surgery. As has been shown repeatedly, urodynamic parameters will improve in patients with colposuspension, whereas a vaginal procedure tends to worsen those parameters. Operative lateral urethrocystography confirms that, by colposuspension, the apex of the vesicourethral junction becomes elevated and fixed onto the symphysis pubis better than by vaginal repair. Moreover, the posterior vesicourethral angle could be diminished much more by abdominal surgery than by the vaginal one. The comparison of the changes caused by surgery of the urodynamic and morphological findings in postoperatively cured and recurrent incontinent patients showed significant differences only in the morphological findings. In vaginally treated patients, the urodynamic and morphological changes were not significantly different, although there seemed a trend towards such differences. As a prognostic criteria for successful surgery the grade of incontinence in the patient's history was not efficacious. For the evaluation of successful surgery, the preoperatively obtained urodynamic parameters UVDR, x2UVDS and DepQ were of greater importance than the TF. Morphologic abnormalities such as a cystocele, funneling of the proximal urethra, vertical and rotatoric descensus were found pre- and postoperatively in recurrent incontinent as well as in cured patients. Therefore these cannot be used as a prognostic criteria. The situation is similar for the height of the vesicourethral angle.(ABSTRACT TRUNCATED AT 250 WORDS)