The aim of this thesis was to determine the yield and some agronomic properties of maize hybrids of different FAO groups and to analyze the differences between them as well as to determine the influence of the year ie weather conditions on the investigated properties. This paper presents some of the results of a micro-experiment conducted in 2017 in the eastern Croatia region of Gorjani. Commercial domestic and foreign maize hybrids of FAO group 300, 400, 500 and 600 were used in the study, and eight hybrids, two from each vegetation group were analyzed. Rainfall and air temperature data collected from the automatic meteorological station in the field experiment were used to analyze weather conditions during the maize growing season. The vegetation year was extremely warm and drier compared to the reference perennial average (1961-1990), with irregular rainfall distribution and a considerable deficit was observed in the first and second decades of July and August, during the most sensitive stages of maize development. All hybrids achieved high yields varying from 9.1 to 14.2 t/ha. The highest yield was obtained by the H6 hybrid from FAO group 500, which also showed the highest grain share in the maize ear (89.5%). The share of grains on the ear, which is related to the number of grains per ear, influenced the yield height independently on the FAO group. The lowest yields were achieved by the hybrids with the lowest grain share, one of which belonged to FAO group 400 and the other to FAO group 600. Generally, the yield level did not depend on the FAO group, as for example, the two earliest hybrids of FAO group 300 averaged the higher yield compared to the two FAO 600 hybrids, which may be due to the high temperatures at their most sensitive phase. In some hybrids, a high proportion of barren plants causes a lower yield.