BACKGROUNDThe square suture technique to achieve hemostasis for postpartum hemorrhage has been described in the medical literature. In a prior report of 23 cases, there were no complications from the technique.CASEA young woman with an gravida 1 para 0 with an uncomplicated prenatal course presented at 40 weeks' estimated gestational age in active labor. Cesarean delivery was performed for arrest of dilatation and was complicated by postpartum hemorrhage unresponsive to medical therapy and uterine artery ligation. Several hemostatic square sutures were placed, obtaining hemostasis. The patient presented 4 weeks postpartum with pain and mucopurulent discharge. Pyometrium was discovered at the time of dilation and curettage.CONCLUSIONPyometrium may result from the use of hemostatic square suture technique for control of postpartum hemorrhage.