As cosmetic procedures receive increasing attention from the media, female genital cosmetic surgery (FGCS) has become quite popular in Korea. The safety and efficacy of these surgeries and procedures have yet to be thoroughly documented. We report a case of a 47-year-old woman who underwent a vaginal sling implantation, which resulted in the misdiagnosis of a rectal subepithelial tumor during endoscopic mucosal resection (EMR). This patient suffered an iatrogenic rectal perforation during the EMR, which necessitated an exploratory operation. The sling implant was removed via the vaginal approach, and a primary repair of the vaginal and rectal walls was performed. The patient subsequently showed no sign of complication at her 6-month follow-up. Patients need to be educated about the importance of reporting a history of FGCS prior to undergoing surgical or endoscopic procedures. Also, physicians have to check the medical history of patient thoroughly to avoid misdiagnoses and unnecessary treatment.