Midurethal sling procedures are gaining popularity as the treatment of choice for stress urinary incontinence. Complications that were described include bladder perforation, urinary retention, pelvic hematoma and suprapubic wound infection. Sling erosion and pelvic abscess are rare complications of midurethral slings. We report the first case of an abscess formed within the wall of the urinary bladder, 7 months following a midurethral sling procedure.