Objective: The objective of this study was to identify factors associated with mesh erosion after placement of a transobturator sling for correction of stress urinary incontinence (SUI). Design: Between 2006 and 2008, a consecutive series of patients underwent surgery for SUI. A retrospective analysis was performed and included baseline, surgical, postoperative, and complication data. Materials and Methods: A total of 69 patients underwent surgery for SUI by placement of a polypropylene mesh sling using the transobturator approach. Demographic and medical history data were collected by interview at baseline, 1 month, 6 months, and 1 year after the procedure. A speculum examination to screen for mesh erosion and infection was performed at each postoperative visit. Comparisons between groups were performed using a v 2 and unpaired Student's t-test. The level of significance was set at p < 0.05. Results: There were 5 (7.2%) mesh erosions reported within 1 year of surgery. Forty-two (60.9%) patients had concomitant surgeries. Age, parity, menopause status, hormonal therapy, body mass index, diabetes mellitus, vaginal trophism, previous and concomitant surgery, and perioperative complications were not associated with mesh erosion. Univariate analysis only identified previous surgery for SUI (3.6 versus 33.3%; p = 0.002) and perioperative inadvertent vaginal transfixation (4.5 versus 66.7%; p < 0.001) as significant factors associated with vaginal erosion. Conclusions: Previous surgery for SUI, and perioperative inadvertent vaginal transfixation, are risk factors for vaginal mesh erosion after transobturator sling placement. ( J GYNECOL SURG 29:231)