The article describes the effect of 8-hydroxyquinoline (8HQ) on C. perfringens and Bifidobacterium spp. The effect was examined in both native and autoclaved ileal contents of broiler chickens in 8HQ concentrations ranging from 32 to 2048 ug/ml. Results showed a clear selective effect of 8HQ towards C. perfingens, when compared to bifidobacteria. The results, howerer, need to be confirmed by the experiment on broiler chickens. Furthermore, a more detailed toxicology is needed to perform.