Retropubic midurethral sling (MUS) is safe and effective surgery used for the treatment of stress urinary incontinence in women. Bladder neck perforation is a rare intraoperative complication. If this complication missed in intraoperative cystoscopy may have serious morbidity. A 52-year-old woman underwent a retropubic MUS. She presented with early and unusual symptoms such as suprapubic and labial cellulitis and urine leakage through the suprapubic incision 1 week after surgery which was due to a missed bladder neck perforation during surgery. In cystoscopy after MUS revealed mesh traversing the bladder neck and it was removed. The missed bladder perforation may have early and unusual symptoms and cystoscopy must be done more carefully and obsessively in patients with risk factors.