The study described diagnostic and therapeutic processes for an exceptional congenital female genital anomaly involving a 15-year-old girl with progressive dysmenorrhoea and intense abdominal pain, and analyses pathogenesis of embryological anomalies associated with uterine duplicity (UD). Diagnostic methodology is analysed; treatment is described; and recommendations are provided. For the study of anomalies such as UD, we recommend the use of an ultrasound, vaginoscopy, MRI and laparoscopy imaging. Keeping in mind that hemihysterectomy should only be performed in cases with endometriosis or other unusual circumstances, surgical treatment should be avoided. A complete study based on gynaecological examination and ultrasound should be performed in adolescents with severe and progressive dysmenorrhoea. Based on the findings, imaging tests such as MRI and, if necessary, laparoscopy coinciding with menstruation, should be conducted before opting for surgical treatment.