The aim of this work was to compare the differences in the determination of nutrients by portable near-infrared reflectance (NIR) spectrometer and chemically in 4 maize hybrids grown in two localities in 2018 to 2021. The nutritional values determined by the spectrometer were, compared to the chemical analysis, lower for the content of dry matter (36.0 vs. 37.1%), NDF (39.7 vs. 44.8% in dry matter) and N-substances (6.52 vs. 7.95% in dry matter) and higher in starch content (35.6 vs. 29.4% in dry matter). For these parameters, it is necessary to calibrate the AgriNIR spectrometer according to the obtained values and continue the research. There were statistically significant differences between sites in the content of NDF, N-substances and ash. There were no differences between the hybrids, and on the contrary, there were differences between the individual years for all determined nutrients.