Women with genuine urinary stress incontinence not associated with POP will be enrolled and randomized in three groups (arm 1, arm 2 and arm 3). All patients eligible will undergo baseline assessment consisting of anthropometric, clinical, hormonal, ultrasonographic and urodynamic evaluations. At time of surgery, all patients will be randomized in three surgical treatment groups (arm 1, 2 and 3). Patients of arm 1 will be treated with positioning of Ajust (Bard Urological Division, Covington, GA, USA), patients of group 2 will be treated with positioning of MiniArc (AMS, Minnetonka, MN, USA) and patients of arm 3 will be treated with positioning of TVT Secur System (Ethicon, Somerville, NJ, USA).