Background: Exposure to dust is associated with a number of activities of the mining industry at every stage of the output process. Crushing machines, paving loaders, drilling blast holes, loading and transportation of excavated material are the major sources of dust emissions. The purpose of this study was to assess occupational exposure to silica dust in the hard and brown coal mines in Poland. Materials and Methods: Based on the measurements of inhalable and respirable dust concentrations, performed by industrial hygiene laboratories in various branches of Polish industry from 2001 to 2005, a detailed analysis of exposure to dust in the all operating coal mines was carried out, taking into account specific workposts. Measurements were made according to current standards; the Taverage dust concentrations, degree of dispersion, range of results and the percentage of measurements exceeding occupational hygiene standards by specific workposts were calculated. Results: The highest concentrations of inhalable (8.25 mg/m3) and respirable (3.11 mg/m3) dusts and the highest percentage of exceedances (74%) were noted in workers of hard coal mines, employed directly in the mining process. In the brown coal mines, slightly lower concentrations were found, and the highest levels of both dust fractions were obtained for workers involved in the transportation of raw material (inhalable dust, 4.13 mg/m3 and respirable dust, 1.02 mg/m3). Conclusions: Exposure to dust in Polish coal mines is still a major problem of industrial hygiene and occupational medicine. Particularly high concentrations of dust, often exceeding the hygiene standards, were found in underground mines at workposts directly related to the output and transport of raw materials and machinery operation. Med Pr 2010;61(3):287-297