The frequency of a bladder foreign body in the female is lower than in the male, and bladder stones attached to foreign bodies such as non-absorbable suture material are not common. Moreover, vesicovaginal fistulas due to migration or puncture of suture materials into the bladder are rare. In this report, we present a case of bladder stone and vesicovaginal fistula formation in a 29-year-old female patient who had been treated with the McDonald operation for an incompetent internal os of the cervix (IIOC) during pregnancy. The patient was successfully treated by cystoscopic removal of the bladder stone with suture material and conservative treatment for the vesicovaginal fistula.