Heat pipes have been widely used as one of the alternative methods to absorb more heat in the cooling systems of electronic devices. To improve the thermal performance of heat pipes, the practice of using various combinations of heat pipes and nanofluids has been widely observed. The purpose of this research was to determine the concentrations and the types of nanofluids that can best enhance the thermal performance of screen mesh wick heat pipes and to determine the effect of coatings on the structure of the screen mesh wick after using nanofluids as the working fluid. In this research, screen mesh wick heat pipes were manufactured and tested to determine the thermal resistance of nanofluids such as Al ₂O ₃-water, Al ₂O ₃-ethylene glycol, TiO ₂-water, TiO ₂-ethylene glycol and ZnO-ethylene glycol charged in the screen mesh wick heat pipes. The concentration of the nanoparticles was varied from 1% to 5% of the volume of the base fluid. The screen mesh wick heat pipe with the best performance was that which used Al ₂O ₃-water nanofluid with 5% volume concentration. Using nanofluids in the heat pipes resulted in the formation of a thin coating on the screen mesh surface from the element of the nanoparticles. However, the thin coating promotes good capillary structure. The higher thermal performance of heat pipes charged with nanofluids proved the potential of nanofluids as a substitute for conventional working fluids. This finding makes nanofluids attractive as working fluids in screen mesh wick heat pipes.