This experiment was conducted with 480 Hubbard JA 957 one-day-old broiler chicks to determine the effects of adiCox®AP, a plant coccidiostat, and monensin on production parameters and meat quality. The birds were randomly allocated to three experimental diets: (A) with the plant coccidiostat adiCox®AP; (M) with monensin, an ionophore coccidiostat; and (C) the control group without coccidiostats. The birds were reared on litter until 63 days of age. The bodyweight of chicks was recorded at the ages of 1, 12, 24, 42 and 63 days. The feed conversion ratio (FCR) and mortality ratio were calculated. There were no significant differences in bodyweight and FCR of birds tested across the experimental groups. In particular feeding groups, the mortality rate ranged from 2.60% to 4.33%, with the lowest number of deaths being noted in the groups receiving the plant coccidiostat (2.6%), whereas the highest mortality rate was recorded in the control group. The type of coccidiostat had no significant effect on the chemical composition of breast muscles. However, the leg muscles of the control chickens were characterized by a significantly higher content of protein (19.4%), compared with the groups receiving coccidiostats in the feed mixtures (19.1% in A and 18.6% in M). The plant coccidiostat effected a higher water-holding capacity (52.2%) and a lower cooking loss (6.9%) in the leg muscles of the birds. The administration of the plant feed supplement adiCox®AP significantly decreased the mortality rate of broiler chickens without compromising other production traits. The results also show that the applied plant preparation is an excellent alternative to antibiotic growth stimulants.