The efflux pump system has been suggested as an important mechanism in the drug resistance of Mycobacterium tuberculosis (MTB). In this study, molecular analysis of five genes in the efflux pump system of MTB isolates from Korean patients was performed in order to identify appropriate molecular targets. In this study, 35 culture-positive specimens were included. PCR was performed for five efflux genes, mmpL7, efpA, mmr, p55 and tap-like gene. In the 35 clinical isolates, molecular analysis of five kinds of efflux pump genes was performed. Only one clinical isolate showed negative PCR results for all five efflux pump genes. All the rest 34 isolates presented concurrent positive results for the five efflux pump genes. In the near future, gene expression study with quantitative PCR should be performed using these genes. (Ann Clin Microbiol 2014;17:65-68)