Tonsillectomy is a frequent operation in otolaryngology, and the most serious complication is post-tonsillectomy hemorrhage. This time, we reviewed 246 patients who underwent tonsillectomy performed by the same surgeon. Postoperative hemorrhage occurred in 17.8% of patients ; the hemorrhage group was older, and the indication was more common for patients with chronic tonsillitis. The most common time of occurrence was after discharge, and the longest was 8 days after surgery. In addition, hemorrhage was more frequent among specialists than general doctors. Since hemorrhage was particularly common on the third day after discharge, we consider that it is important to give the patient sufficient guidance on diet and lifestyle. In addition, the reason why hemorrhage was common among specialists may have been that the surgery was performed independently and that careful procedures and hemostasis could not be confirmed, so we consider that self-checking during surgery is necessary.