The aim of the study was to determine whether replacing soybean meal with 3% or 6% fermented soybean meal would positively affect blood metabolites and redox status of broiler chickens. The experiment was carried out on 600 broiler chickens assigned to three experimental groups of 200 chickens each (10 replications of 20 individuals each). In the control group, soybean meal (SBM) was the main source of dietary protein, whereas the remaining groups were fed diets in which soybean meal was partially replaced with 3% or 6% fermented soybean meal (FSBM-3%, FSBM-6%). The fermentation of the SBM contributed to an increase of