Obstructing lesions of vagina, such as transverse vaginal septum, are rare anomalies. In this paper, we report a case of posttraumatic transverse vaginal septum. The patient was a 14-year-old girl who had a transverse vaginal septum because of repaired perineal trauma happened during earthquake that hit Bam city of Iran, when she was three years old. Post-traumatic vaginal septum had resulted in development of a massive hematometra. To our knowledge, this is the first report of urinary incontinence due to massive hematometra, which resulted from a posttraumatic vaginal septum. The rareness and diversity of clinical presentations of vaginal obstructing lesions can lead to misdiagnosis. The patient might refer to different medical and surgical specialists. So, knowing the symptoms is necessary for its early diagnosis. The probability of vaginal obstructing lesions in peripubertal girls with lower urinary tract symptoms should always be considered.