BACKGROUND: Noise pollution is one of the most important occupational pollutants in heavy-vehicle drivers. Therefore, this epidemiological research was conducted with the aim of determining the prevalence of hearing loss in heavy-vehicle drivers in Iran. METHODS: This cross-sectional research was conducted on 65,533 heavy-vehicle drivers including truck and intercity bus drivers from February 2006 to March 2016. The air and bone threshold of pure tone was measured for each ear at 0.5, 1, 2, 3, 4, 6, and 8 kHz by a skillful radiology expert. The obtained data from this research was analyzed in SPSS software using statistical tests such as descriptive analysis and paired t test. RESULTS: Mean (standard deviation) of hearing loss in left and right ears of all people was 23.02 (8.25) and 22.48 (7.86), respectively. Paired t test showed that hearing loss difference in left and right ears was significant (P < 0.001). Mean and standard deviation of paired t test showed that hearing loss difference in left and right ears was significant in all frequencies except 1000 Hz (P < 0.001). CONCLUSION The findings of this research generally showed that 26.8% of the studied drivers have hearing loss. Hearing loss in the left ear was more than right ear.