Amaranth (Amaranthus spp.) is a promising alternative crop that is gaining more and more popularity and distribution throughout the world. We set a goal to find out how the doses of mineral fertilizers affect the yield and quality of amaranth grain in the wet and warm climate of the Western Forest Steppe of Ukraine. We conducted research from 2020-2022 on the experimental field of the Lviv National Environmental University (LNEU - Dublyany). The soil of the experimental field is Grayic Luvic Phaeozem. The experiment comprised seven different fertilizer treatments: N0P0K0, N40P20K40, N80P40K80, N120P40K80, N160P60K120, N200P80K120, N200P80K160. The tested plant was amaranth of the Kharkivskyi 1 variety. A systematic increase in fertilizer rates, particularly nitrogen, led to a gradual rise in amaranth grain yield. In the control without fertilizers, the yield was 2.31 Mg ha^-1. With an increase in fertilizer application, it rose by 2.57 Mg ha^-1, reaching 4.88 Mg ha^-1 at the highest fertilizer rate N200P80K160. The grain bulk density was higher (790 g l^-1) in the variants without fertilizers, the lowest – when N200P80K160 and N200P80K180 were applied, where it was 755 g l^-1 and 750 g l^-1. The protein content in amaranth grains increased from 16.2% to 18.9%, reaching its peak under the influence of an increase in mineral fertilizer rates from N40P20K40 to N200P80K160. Starch content decreased from 67.4% on the object without fertilizers to 64.8% when applying the highest rates of fertilizers – N200P80K120 and N200P80K160. Statistical models of interrelationships showed that the doses of mineral fertilizers, especially nitrogen, have a strong influence on the indicators of yield and grain quality of amaranth in the warm and humid climate of western Ukraine. High rates of fertilizers significantly increase yield, but negatively affect grain bulk density and starch content, significantly increase the proportion of protein.