Myringotomy and ventilation tube insertion are the most frequently performed otologic operation and are indicated in otitis media with effusion, negative middle ear pressure, tympanic membrane atelectasis and recurrent acute otitis media for ventilation and drainage of middle ear fluid. The complications are postoperative otorrhea, atrophic tympanic membrane, tympanosclerosis, permanent perforation of tympanic membrane, ossicular disruption, cholesteatoma and obstruction of ventilation tube. The postoperative otorrhea is the most common complication and the incidence is 15 to 74%. Authors analyzed the incidence of postoperative otorrhea in 162 patients(248 ears, 458 operations) who were taken myringotomy and ventilation tube insertion during the period of May, 1986 through March, 1988 at Department of Otolaryngology, Chunan Hospital, College of Medicine, Soonchunhyang University. The results were as follows ; 1) Incidence of the postoperative otorrhea were 28 patients in 162 patients(17.3%), 31 ears in 248 ears(12.5%) and 31 operations in 458 operations(6.8%). 2) Site distribution of otorrhea was more common in unilateral(17.1%) than bilateral(10.5%). 3) Sex distributions showed 15 patients in 89 patients(16.9%), 17 ears in 138 ears(12.3%) in male and 13 patients in 73 patients(17.8%), 14 ears in 110 ears(12.7%) in female. 4) Age distribution was more common in adults(18.8%) than children(14.8%). 5) Seasonal distributions were more common in fall(8 patients in 31 patients, 25.8%) and winter(10 ears in 53 ears, 18.9%). 6) Distribution of operation was the most common in ventilation tube insertion, only(12.7%). Post-operative otorrhea in ventilation tube insertion(14.4%) was more than that in myringotomy(1.5%). 7) Distribution in number of operation was not significant. 8) In middle ear fluid, the incidences of postoperative otorrhea were 20.9%(purulent discharge), 13.0%(mucoid discharge) and 12.8%(serous discharge) in frequency. 9) Treatments of postoperative otorrhea were conservative treatment in 23 ears and culture and sensitivity test for bacteriology, tube removal and conservative treatment in 8 ears.