Pulsed magnetic-technology has been developed for pelvic floor muscle strengthening for the treatment of urinary incontinence. This report includes an update of the prospective multicenter study of extracorporeal magnetic innervation (ExMI) therapy for stress incontinence and a discussion of the possible mechanisms of action. Issues of patient selection for ExMI therapy will also be discussed. One hundred and eleven women with demonstrable stress urinary incontinence were studied. The mean age was 55 +/- 13 years, and the mean duration of symptoms was 11 years. Ninety-seven completed ExMI therapy and analysis. Evaluation before treatment included bladder diaries, dynamic pad weight test, urodynamics, and a quality-of-life survey. For treatment the patients were seated fully clothed in a Neocontrol chair with a magnetic field therapy head in the seat. Treatment sessions were for 20 minutes, twice a week, for 6 weeks. After ExMI therapy, all of the measures were repeated at 8 weeks, including the dynamic pad weight testing and quality-of-life survey. At 6 months, further data were added, including repeat bladder diary, pad use, and quality-of-life survey. Forty-seven women completed 6 months of follow-up; of the 47, 13 patients were completely dry (28%) and 25 used no pad or less than 1 pad per day (53%). Pad use was reduced in 33 patients (70%). The median number of pads was reduced from 2.16 to 1 per day (Wilcoxon signed rank test, P <0.005). The frequency of leak episodes was reduced from 3.0 to 1.7 at 6 months (Wilcoxon signed rank test, P = 0.004). Detrusor Instability was demonstrated in 10 before and 6 after ExMI (P <0.05). ExMI offers an alternative approach for the treatment of urinary incontinence. ExMI therapy is effective for both stress and urge incontinence. The best results are achieved in those patients who use no more than 3 pads a day and have had no prior continence surgery. UROLOGY 56 (Suppl 6A): 82-86, 2000. (C) 2000, Elsevier Science Inc.