Benzylpenicillin potassium yana da tasirin antibacterial mai kyau akan streptococcus, streptococcus pneumoniae da staphylococcus wanda basa samar da enzyme na penicillin. Tana da matsakaiciyar kwayar cuta ta bakteriya game da enterococcus. Neisseria gonorrhoeae, neisseria meningitidis, corynebacterium diphtheriae, bacillus anthracis, actinomyces bovis, streptococcus candida, listeria listeriae, leptospira da treponema pallidum suna kula da wannan samfurin. Hakanan wannan samfurin yana da wasu cututtukan antibacterial akan haemophilus mura da bordetella pertussis. Sauran nau'ikan gram-negative aerobe ko facetative anaerobe suna da ƙwarewa ga wannan samfurin. Wannan samfurin yana da kyakkyawan tasirin kwayar cuta akan clostridium, anaerobe na narkewar abinci streptococcus da bacillus .