One of the most important problems concerning health and safety in mining is prolonged exposure to high levels of noise. Development of modern mechanized operations in mining industry has been considerably decreasing the physical burden of work, but the most undesired and unavoidable by-product of these operations is the generation of high levels of noise. The specific objective of this study was to estimate occupational noise exposure levels of mine workers by dividing the workers into homogeneous exposure groups (HEGs) performing similar tasks under similar working conditions in Zonguldak Bituminous Coal Mines in Turkey. The A-weighted equivalent noise level (L-Aeq) and exposure time were measured for each task performed by workers using Class 1 type Rion NL-31 integrating and logging sound level meter. The homogeneity of the groups was tested statistically using one way analysis of variance (ANOVA). The normality of noise levels obtained for HEGs was investigated using one sample Kolmogorov-Smirnov test (K-S). The daily noise exposure level of workers was estimated by using the method described in the standard ISO 9612 (1997). The findings of this study showed that the daily noise exposure levels (L-EX,L-8h) of mine workers ranged from 75.3 to 101 dBA. The five occupations found to be most at-risk owing to daily noise exposure levels were driller/drilling operator (L-EX,L-8h: 101 dBA), development stoping (L-EX,L-8h: 97.4 dBA), carpenter (L-EX,L-8h: 97 dBA), ram operator/pumper (L-EX,L-8h: 95.8 dBA), and mechanic worker of mining machinery plant (L-EX,L-8h: 94.6 dBA). They were followed by casting from mining machinery plant exposure group and belt conveyor worker from surface exposure group who are exposed to daily noise exposure levels of 94.5 and 93.2 dBA respectively. (C) 2013 Institute of Noise Control Engineering.