Two hundred and seventy seven patients presenting genuine USI were divided into 3 groups based on a positive history for USI (group I), positive history and clinic for USI (group II), and positive history, clinic and urethral profile of USI (group III). When compared to a group of women without USI, the values for the FL and MUCP diminish progressively from group I to group III, giving evidence of increasingly severe impairment of the muscular-elastic environment in the urethra. Only in group III is the transmission factor (F) reduced, attesting a loosening/distension of the posterior pubo-urethral ligaments. The tonomeric values calculated for the patients with recurring USI following previous surgical correction (group IV) are comparable to values for group III. A scoring of severity of USI is proposed serving as a basis for establishing the criteria determining the indication for surgery and the post-operative prognosis before an intervention to correct USI is undertaken.