Microorganisms affect every aspect of our lives. Especially pathogenic and resistant microorganisms are microorganisms that prevent us from living a healthy life. As a result of the unnecessary use of antibiotics, bacterial resistance has emerged. One of the bacterial resistance mechanisms is efflux pumps. In this in vitro study, it was aimed to observe the inhibition of the efflux pumps by testing 3 compounds on a total of 8 strains, including Klebsiella pneumoniae, Providencia rustigianii, Shigella flexneri, 4 clinically isolated Escherichia coli, and E. coli ATCC 25922 having active efflux pumps. The plant derived compounds used were naringenin, quercetin and umbelliferone. Cartwheel method was applied by using MIC/2 concentrations of the compounds. At the end of the test, UV light was used to observe the efflux pump inhibition activities of phytochemicals. According to the results of the study; the efflux pump inhibition activity was observed only for naringenin. A further study is recommended to determine the interaction mechanisms of naringenin with specific efflux pump families.