Tonsillectomy is a commonly performed procedure with an accepted risk of posttonsillectomy hemorrhage (PTH) approaching 5%, but catastrophic effects of hemorrhage are exceedingly rare. A variety of surgical techniques and hemostatic agents have been used to reduce the rate of hemorrhage, although none eliminate the risk. Numerous patient, surgical, and postoperative care factors have been studied for an association with PTH. The most consistent risk factors for PTH seem to be patient age and coagulopathies. Surgeon skill and surgical technique are most consistently associated with primary PTH.