Post-operation results of stress urinary incontinence treatment have been assessed and subjected to statistical analysis in 667 patients. The elaboration of the results was based on case history data, inquiries and control ambulatory examinations. Diagnostic procedures included sphincterometry, cystometry, cystoscopy, cystography and provocation test like coughing. Vaginal and urine biocenosis was always assessed microbiologically. The Marshall-Marchetti operation as modified by Durfée and Burch was made within the space of Retzius. Complementary procedure consisted in suturing levator ani muscles after previous bilateral opening of pararectal space within perineum. Third pair of sutures was placed according to the authors' own modification during the Durfée operations. The results of surgical treatment of SUI performed by the authors do not differ in principle from those reported by others. A small number of relapses the authors ascribe to local and systemic processes of aging which diminish the effectiveness and the value of previously made correction of urethra and of the bladder bottom topography.