During combine harvesting of 5 various cereal crops (rye, barley, oats, buckwheat,ncorn) 24 samples of grain and 24 samples of settled grain dust were collected on farms located in the Lublin province of eastern Poland. The samples were examined for the concentration of total microfungi, Fusarium species, deoxynivalenol (DON), nivalenol (NIV), and ochratoxin A (OTA). Microfungi able to grow on malt agar were present in 79.2% of grain samples and in 91.7% of grain dust samples in the concentrations of 1.0-801.3 × 10³ cfu/g and 1.5-12440.0 × 10³ cfu/g, respectively. The concentration of microfungi in grain dust samples was signifi cantly greater than in grain samples (p<0.01). Fusarium strains were isolated from 54.2% of grain samples and from 58.3% of grain dust samples in the concentrations of 0.1-375.0 × 10³ cfu/g and 4.0-7,700.0 × 10³ cfu/g, respectively. They were found in all samples of grain and grain dust from rye, barley and corn, but only in 0-16.7% of samples of grain and grain dust from oats and buckwheat. DON was found in 79.2% of grain samples and in 100% of grain dust samples in the concentrations of 0.001-0.18 μg/g and 0.006-0.283 μg/g, respectively. NIV was detected in 62.5% of grain samples and in 94.4% of grain dust samples in the concentrations of 0.004-0.502 μg/g and 0.005-0.339 μg/g, respectively. OTA was detected in 58.3% of grain samples and in 91.7% of grain dust samples in the concentrations of 0.00039- 0.00195 μg/g and 0.00036-0.00285 μg/g, respectively. The concentrations of DON, total fusariotoxins (DON + NIV) and OTA were signifi cantly greater in grain dust samples than in grain samples (p<0.05, p<0.05, and p<0.001, respectively). The concentration of Fusarium poae in the samples of rye grain and dust was signifi cantly correlated with the concentrations of DON (p<0.05), NIV (p<0.01), and total fusariotoxins (p<0.05). Similarly, the concentration of Fusarium culmorum in the samples of barley grain and dust was signifi cantly correlated with the concentration of total fusariotoxins (p<0.05). A signifi cant correlation was also found between the concentration of total fungi grown on malt agar and the concentration of OTA (p<0.05). In conclusion, although the concentration of DON, NIV and OTA in the samples of grain dust collected from 5 various cereals on farms in eastern Poland was not large, the persistent presence of these mycotoxins in over 90% of examined samples poses a potential health risk of chronic respiratory intoxication for exposed grain farmers.