Coccidiosis is a critical disease in the poultry industry worldwide. Producers apply different strategies to control and prevent this disease. Herbal drugs are suitable remedies for reducing losses associated with coccidiosis in poultry. The present study aimed to evaluate the effectiveness of an herbal mixture in preventing coccidiosis. A total of 160 broiler chickens were divided into four treatment groups, with five replicates for each. Experimental infection of all groups, except group D, was carried out with mixed Eimeria species (E. tenella, E. necatrix, E. brunetti, and E. maxima) on day 14. Broiler chickens in group A were given an herbal mixture (75% Quercus infectoria, 16% Artemisia annua, and 9% Allium sativum) as feed additives during the rearing period, and group B was treated with Monensin. No treatment was applied to group C after the chickens were experimentally infected with mixed Eimeria spp. Group D was used as the negative control since chickens in this group were not infected or sick during the experiment. Body weight gain, feed conversion ratio (FCR), mortality rate, intestinal lesion scoring, and oocyst count per gram (OPG) were evaluated in this study. The results of the present study revealed that the highest mean body weight was gained in group D, followed by chickens in group A. The best FCR results were attributed to chickens in group D, followed by group B. In this study, both drugs decreased mortality rate, intestinal lesion scores, and OPG in the treated chickens. In conclusion, this herbal mixture can reduce coccidial lesions. Keywords: Broiler, Coccidiosis, Herbal mixture, Prevention