A field experiment was set up in 2007 in a split-plot design to investigate the effect of various NPK fertilizer doses on the total antioxidant capacity (TAC) of fresh leaf tissue of the Polish amaranth varieties Rawa and Aztek, cultivated for seed, and of the soil they were cultivated on. The experiment was conducted with three replicates. The following combinations of macroelement doses were applied: I: N – 50 , P – 40, K – 40 kg ha-1; II: N – 90, P – 60, K – 60 kg ha-1; and III: N – 130, P – 70, K – 70 kg ha-1. The total antioxidant capacity (TAC) of the soil and amaranth leaves was determined using the method described by Rice-Evans and Miller, as modified by Bartosz. Organic carbon content was determined as well. In most of the cases the fertilization (NPK) caused an increase in total antioxidant capacity of the soil under amaranth cultivation. The highest total antioxidant capacity in the soil examined (compared with the control) was found with combination III of NPK fertilizers for soil under Rawa cultivation, and with combination I for the Aztek soil. The total antioxidant capacity of amaranth per unit fresh leaf mass was dependent on the variety and on the doses of the macroelements applied. The highest total antioxidant capacity in Rawa per unit fresh leaf mass was observed with combination III, while for the Aztek variety the highest TAC was found with combination I. Statistical analysis showed significant dependencies between TAC of the soils and leaves and the level of fertilization, as well as between the TAC of the soil and of amaranth leaves.