BACKGROUND Postpartum hemorrhage, immediate or delayed, is a leading cause of maternal death. The most common etiologies are retained products of conception, infection, and subinvolution of the placental implantation site. METHODS A 31-year-old woman, gravida 1, para 0, had an uneventful pregnancy after infertility treatment. She was delivered by intrapartum Caesarean section because of arrest of descent. Twelve days after delivery she had profuse, intermittent vaginal bleeding, but physical examination and pelvic ultrasound failed to reveal the cause. Angiography was performed and showed a left uterine artery pseudoaneurysm that was successfully treated with arterial embolization. CONCLUSIONS Use of uterine angiography and embolization at an early stage in the search for the etiology of postpartum hemorrhage helps to decrease morbidity and mortality.