Objectives: This study was conducted to investigate the incidence rate of noise-induced hearing loss (NIHL) in Korean youths using the National Health Insurance Data Methods: We obtained the case of NIHL with the National Health Insurance Data and calculated the incidence rate of NIHL after classifying them by year (from 2005 through 2008), age, gender, birth cohort. Results: The age-adjusted incidence rate by year of NIHL per 100,000 population increased by 40.6% from 13.8 persons in 2005 to 19.4 persons in 2008, which showed a increasing trend every year. In particular, the incidence rate per 100,000 population among the adolescents (15-19 years of age) shot up by 78.2% from 8.7 persons in 2005 to 15.5 persons in 2008. According to the incidence rate by birth cohort of NIHL, the birth cohorts showed the gradually increase in incidence rate as time passed by. Adolescents in early 20s (20-24 years of age) had a higher incidence rate than teenage and men had a higher incidence rate than women. Conclusions: The results suggest that incidence rate of NIHL in Korean youths has rapidly increased among adolescents. Therefore, it is required to educate adolescents about the risk of hearing loss due to noise, establish program to prevent NIHL among adolescents and provide them with health education on hearing loss prevention.