The nematode Enterobius vermicularis is normally found within the human gastrointestinal tract. Pregnant females migrate towards the anus to lay their eggs. During this nocturnal migration some worms find another adjacent orifices, most commonly the female genitourinary tract. The presented case is a 34-year-old woman referred to the Colposcopy Unit of the Antiguo Hospital Civil of Guadalajara Fray Antonio Alcalde by cervical erosion. With the colposcopy a live worm in the vagina was visualized; it was identified as a gravid female of Enterobius vermicularis by microscopy. The diagnosis of ectopic enterobiasis was an incidental finding during the colposcopic examination of the patient with diagnosis of ectopy.