The aim of this study was to determine how citrinin (CIT), aflatoxins (AFL B1+B2+G1+G2 ), ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON) concentrations vary under different maize grains storage conditions and how they affect grain quality. Analyses of mycotoxins: AFL B1+B2+G1+G2 , CIT, DON, ZEA, and OTA, and grain quality: dry matter (DM) content, crude protein (CP), crude ash (CA), crude fibre (CF), crude fat, and starch, were performed at the beginning of the experiment and then after 3 and 6 months of storage. The results of the experiment showed that the duration of storage had the greatest influence on the formation of AFL B1+B2+G1+G2 when an average concentration increased about three times after 6 months of storage, regardless of storage conditions. The duration of storage also had a significant effect on CIT accumulation, as it was not detected in the maize grain samples before the experiment, and after 6 months of storage, the concentration ranged from 93 to 184 µg kg -1 . It was also noted that there is no risk of an increase in the concentrations of DON, ZEA, and OTA in maize grains when dried grains are stored well (up to 7% moisture content). The DON concentration after 6 months of storage at 12°C and 20°C and in the warehouse decreased about two times, while at 4°C after 3 months of storage it also decreased, and then after 6 months it increased to the same concentration as at the beginning of the experiment. Throughout the experimental period, ZEA and OTA concentrations were slightly above or below the limit of detection (LOD). The nutrient composition after 6 months of storage was only different after storage at 20°C temperature. The increase in starch content was accompanied by an increase in the DM content. Strong positive correlations were observed: as the concentrations of AFL B1+B2+G1+G2 and CIT increased, so did the DM content, while the crude protein content increased with increasing the DON concentration.