Although used extensively in the assessment of many gynecological conditions, transvaginal ultrasonography is not performed routinely prior to termination of pregnancy in the UK. We describe a case in which surgical evacuation of the uterus failed. Postoperatively, transvaginal ultrasonography demonstrated a bicornuate uterus with a viable pregnancy within the left horn. Subsequent medical termination of pregnancy was successful. This case shows the potential value of transvaginal ultrasonography prior to termination of pregnancy. A prospective trial is needed to assess whether its routine introduction into clinical practice will lead to a reduction in morbidity resulting from termination.