The statistical study was done on 968 cases of tonsillectomy and 21 cases of post-tonsillectomy bleeding which were done at the department of otolaryngology, the National Medical Center during the period of last 10 years from 1965 to 1975. The results were as follows. 1. Total number of tonsillectomy were 968 cases, and among them, 574 cases were male and 334 cases were female. The most common age group of tonsillectomy cases were between 10 to 15 years. 2. The total number of post-tonsillectomy bleeding were 21 cases (2.17%). 3. The number of primary bleeding were 11 cases (1.14% to total tonsilectomy cases) and secondary bleeding were 10 cases (1.03%). 4. In sex incidence, 13 cases were male (61.9%) and 8 cases were female (38.1%). 5. In age distribution, the highest incidence was in the group of 40-45 and followed by group of 35~40 and 25~30. 6. In months distribution, the highest incidence was in April and October as 5.26%. 7. The highest incidence during a day was in the group of dinner time to midnight as 7 cases (33.3%). 8. The most common bleeding site was right tonsillectomized fossa as 10 cases (47.6%). 9. The predisposing factors were umknown cases (52.4%) and remnant of tonsil(14.3%). 10. In many cases (47.6%), the bleeding was controlled by simple compression.