A total of 100 female patients with putative urinary stress incontinence (USI) were surveyed by us. Of these, 27 patients with genuine USI underwent urologic, uroradiologic and urodynamic evaluations before and after their corrective surgery by the technique of Burch. The results of the surgery were assessed clinically and subjectively and compared to the data obtained from postoperative urodynamic analysis. The operation affected significantly the urethral closure pressure and the posterior angle between the urethra and the base of the bladder, bringing about marked clinical improvement in most of the patients. Thus 89.5% of operated patients were cured, while elevated urethral closure pressure was proven in the majority of cases and radiologic examinations showed correction of the anatomic fault in 82% of the women undergoing surgery. Correct diagnosis is the most important antecedent of treatment in female urinary stress incontinence. Any surgical approach which affixes the neck of the bladder and the posterior part of the urethra to a stable support is sufficient to effect correction of the condition, provided the incontinence stems from a weakness in the closure mechanism of the urethra and not from some other cause.