AIM: The aim of this study was to investigate the short and long-term effects of repetitive magnetic stimulation on the sacral roots in a homogeneous group of patients affected by stress incontinence. METHODS: Twenty women with urinary stress incontinence were randomly assigned to an active or a sham stimulation group. Fifteen-Hz repetitive magnetic stimulation of the sacral roots (S2-S4) was applied for 15 min. Patients were treated with magnetic stimulation for 3 days a week for 2 weeks (6 times in all). The clinical outcome was assessed before (T1) and 1 week (T2) and 1 month (T3) after stimulation. Main outcome measures were: the King's Health Questionnaire, the SEAPI-QMM scale and the amount of urinary loss in a 1-h pad test and stress test. RESULTS: At T2 patients in the active stimulation group showed improvement in health perception (P<0.001), social limitation (P<0.01), sleep/energy performance (P<0.05) and severity measure score (P<0.05) not observed in the sham stimulation group; a significant decrease in SEAPI-QMM score was noted only in the active group at T2 (P<0.05). These results were no longer observed at T3. We also observed a decrease in the amount of urine loss quantified with the pad test and stress test in the active stimulation group. CONCLUSION: Repetitive magnetic stimulation of the sacral roots has a short-term effect on some aspects of the quality of life of the patients, but it did not prove effective using quantified measurement.