Optimization process for fabrication of Carbon nanotubes (CNTs) reinforced Polyethylene (PE) fibers by melt spinning has been studied. Three main melt spinning process parameters (spinning temperature, spinning distance, and spinning revolution) are evaluated by the Taguchi’s method to decrease the diameter of fibers. Decreasing diameter of fibers is greater influenced by spinning revolution and distance than spinning temperature. Moreover, fibers in diameter 22 μm (average) are successfully fabricated. Mechanical properties are measured by tensile test machine based on ASTM D3822 for single fibers which were fabricated at optimized melt spinning process parameters. Pure PE polymer fibers and chemically surface modified CNTs reinforced fibers also fabricated for comparison purpose. The interfacial bonding of CNTs with PE matrix is investigated through fracture surfaces image analysis by Scanning Electron Microscopy (SEM).