Chronic tonsillitis has long been one of the most common diseases in the otolaryngologic field. Authors have studied 60 patients who had been admitted for tonsillectomy from June 1980 to August 1981 at the Dept. of E.N.T., Eul Ji General Hospital. We performed direct smears and cultures by swab from the surfaces of both palatine tonsils before tonsillectomy and from the cut surfaces of the tonsils after tonsillectomy. The results obtained were as follows ; 1) From the surface cultures, bacteria were isolated from 54 cases among 60 cases, which were composed of α-hemolytic streptococcus in 24 cases (44.4%), Staphylococcus aureus in 23 cases (42.6%), β-Hemolytic streptococcus in 1 case (1.9%) and Pseudomonas in 1 case (1.9%) in order. 2) From the cut surface cultures, bacteria were isolated also from 54 cases among 60 cases, which were composed of Staphylococcus aureus in 27 cases (50%), α-hemolytic streptococcus in 18 cases (35.0%), β-hemolytic streptococcus in 5 cases (9.0%), Pseudomonas in 2 cases (3.0%) and Klebsiella in 2 cases (3.0%) in order. 3) In 32 cases (53.3%), the same bacteria were isolated from both the surfaces and the deep tissues. 4) For Staphylococcus aureus, the sensitivity test revealed that it is susceptible to Panimycin, Gentamicin, Cephalosporin and Erythromycin, but is resistant to Tetracycline, Penicillin Streptomycin and Ampicillin. For α-hemolytic streptococcus, it is susceptible to Gentamicin, Panimycin, Cephalosporin and Chlorampenicol, but is resistant to Tetracycline, Penicillin, Ampicillin and Minocin. 5) For Pseudomonas, it is susceptible to Panimycin, Tobramycin, Kedacillin and Gentamicin, but is resistant to Tetracycline, Cephalosporin, Kanamycin, Neomycin, Penicillin, Chloramphenicol and Erythromycin.