BACKGROUND: This is to evaluate the noisy environment, and to improve the hearing conservation program by analyzing the status of hearing loss and risk factors which cause hearing loss of Airlines pilots. METHODS: We reviewed Audiometric, Medical and Flying records of total 92 pilots under 55 years old . These subjects selected after excluding pilots with history of ear disease and ototoxic drug administration. The significance of the factors was analyzed by ANOVA and Regression test. RESULT: The mean age of pilots was 39.96 years old and the mean flight time was 5665.39 hours. The noise levels by aircrafts were mean 76.9dB and maximum 144.4dB in B737, mean 78.5dB and maximum 143.2dB in B747. The noise levels by headset were mean 72.1dB and maximum 144.1dB. The mean hearing threshold level was different with age groups. The older in age, the higher in the mean hearing threshold level at high frequency and left ear. It was increased the mean hearing threshold level (dB) at high frequency (4,000 Hz) by total flight time The effect on hearing threshold level at high frequency in left ear was statistically significant in total flight time (p=0.032). CONCLUSION: The noise level of aircrafts could cause noise-induced hearing loss in some pilots. Age and total flight time are within the range of possibility of hearing loss. The result of this study ascertained the possibility of hearing loss due to monaural-headsets on the left ear at 4,000 Hz. It is recommended that an effective hearing conservation program should be provided for the headset-wearing communication pilots.