Didelphys uterus with imperforated obstructed hemivagina is a rare condition. Most often, it is diagnosed a few months after the menarche. Hematocolpos, hematometria and sometimes hematosalpinx are responsible for pelvic pain and dysmenorrhea. Symptoms can be delayed when a fistulisation from the hematocolpos to permeable contralateral vagina is present. Sometimes, diagnosis is not made before adulthood during an infection of the hematocolpos. Useful additional exams include pelvic ultrasound and, in some cases, MRI, which is the best exam to precisely describe the type of malformation. An ipsilateral agenesia of the kidney is always associated. Hysterography can usually demonstrate the fistulous courses. Treatment consists in a large resection of the vaginal septum in order to allow a permanent drainage of the hemiuterus. A laparoscopy should be performed to check for the presence of associated tubal or pelvic damage.