Mature teratomas are usually detected in the ovary, while they are very rarely found in the vagina. Only several cases of vaginal mature teratomas have been reported. In this article, the authors describe the case of a 28-year-old female with dyspareunia for four months diagnosed by MRI. The MRI findings in vaginal teratoma are easily confused with other vaginal cysts. Pelvic MRI is valuable in evaluating the nature of vaginal mass and determining the treatment approach.