We have prepared conductive fibers by coating poly(ethylene terephthalate) (PET) fibers with solutions composed of multi-walled carbon nanotube (MWNT), surfactant and binder, and characterized surface morphology and electrical properties of MWNT-coated PET fibers. FE-SEM images of MWNT-coated PET fibers confirmed that MWNTs were successfully coated on surfaces of PET fibers. It was found that MWNT-coated PET fibers prepared have maximum conductivities of ${sim}10^0;S/cm$. Even after abrasion tests, the electric conductivities of MWNT-coated PET fibers remained in the order of ${sim}10^{-2};S/cm$, which was still much higher than the value (${sim}10^{-13};S/cm$) of neat PET fibers. Overall, it was revealed that the MWNT-coating method can be a efficient process to produce conductive fibers without deteriorating mechanical properties of original fibers.