A clinical observation was made on 20 cases of the otogenic brain abscess treated in Dept. of Otorhinolaryngology, National Medical Center during a period of Mar. 1961 through Aug. 1972 and the following conclusions were obtained. 1) Age distribution showed predilection for age of 11 to 20 with 13 cases (65%). 2) Sex incidence revealed 15 male(75%) and 5 female(25%). 3) The region of the abscess was 14 temporal lobe(70%) and 6 cerebellum(30%). 4) In 17 cases of all these cases, gram negative bacilli were cultured and gram positive cocci were cultured in 1 case. 2 cases were negative in culture. 5) The side of abscess revealed 9 cases of the right and 11 cases of the left side. 6) Cholesteatoma was found in 14 cases(82.4%) out of 17 cases who received radical mastoidectomy, and noticed the exposed dura or sigmoid sinus in 15 cases (88.2%). 7) The duration of the history of otitis media was more than 5 years in 16 cases(80%). 8) The clinical findings revealed nausea and vomiting in the all of the cases(100%), fever in 17 cases(85%), and headache and neck stiffness in 16 cases(80%). 9) The spinal puncture showed increased pressure in 13 cases(65%) and 7 cases(35%) were normal in pressure. 10) Mortality rate was 80%.