A gravida 4 para 1021, 41-year-old woman postcaesarean section at 39 weeks and 1 day with clinically significant haemorrhage required embolisation of unique uterine arterial collaterals. She had persistent haemorrhage after initial bilateral uterine artery embolisation, and on further investigation she was found to have a hypertrophied right round ligament artery. Once successful embolisation of this abnormal right round ligament artery was completed using a combination of Gelfoam and coils, haemostasis was achieved. She had rapid clinical improvement, no complications and no further admissions on postprocedural follow-up over a year and a half later.