In this study the effect of humic substances, garlic (Allium sativum L.), wormwood (Artemisia absinthium) and walnut (Juglans regia) on carcass parameters of broiler chickens were studied. Broiler chickens Ross 308 (n=60) were divided into 3 groups (n=20). The chickens of the control group were fed with complete feed mixtures without any additives. Chickens in the first experimental group E1were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of wormwood. Chickens in the second experimental group E2 were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of walnut.  The carcass weight, weight of heart, liver, gizzard, carcass yield and EPEF were evaluated. The carcass weight was in both experimental groups higher, but no statistically significant (P>0.05) in compare with the control group (values in the order of the groups: 1246.93±172.61; 1352.16±139.89 and 1308.30±166.17 g±SD). In the first experimental group E1 were weight of heart (12.15±2.29 g±SD) and weight of gizzard (41.58±7.44 g±SD) significantly higher (P≤0.05) compared to the control group (9.99 ±1.82; 33.62±5.03 g±SD).