We hereby report a 1-year follow-up on eight women in the first North America trial in which stress urinary incontinence (SUI) was treated with muscle-derived stem cell injections. Mean and median follow-up in this group was 16.5 and 17 months (range 3-24 months). Improvement in SUI was seen in five of eight women, with one achieving total continence. Onset of improvement was between 3 and 8 months after injection. Cure or improvement continued at a median of 10 months. No serious adverse events were reported.