Introduction: the World Health Organization recommends physical therapy in patients with mild to moderate Urinary Incontinence (UI) as the first line of treatment. Aim: Evaluate the effect of electrical stimulation on muscle contraction of the pelvic floor and quality of life of women with stress UI (SUI). Methods: experimental study with 75 female patients randomly divided into: G1: electrical stimulation therapy with kinesitherapy; G2: kinesitherapy; G3: control group. Parameters evaluated: anthropometric measurements, physical examination of the pelvic floor (AP), pelvic floor muscles (AFA) and the degree of contraction of the AP (CAP) by the activity of the muscles [Type I (TI) and Type II (TII)] and Quality of life (QOL). Intervention consisted of 12 sessions, two sessions per week for six weeks. Descriptive statistics were used and the Student's t test or Wilcoxon paired test for the intra-group analysis. For the inter-group analyses, we used the Kruskal Wallis followed by the Mann-Whitney (AFA and QOL) and two-way ANOVA followed by Scheffe post hoc test (CAP). The p< 0.05 was adopted for statistical significance. Results: there was a significant difference in: AFA TI and AFA TII (G1 x G3 and G2 x G3); CAP TI (G2 x G3). There was a significant reduction in all domains of QOL in G1 and G2 except for DOM 6 in G2. The G3 group did not display any significant results. Conclusions: both physical therapy treatments (G1 and G2) were effective in the improvement in pelvic floor muscular functioning and in quality of life.