[show abstract][hide abstract] ABSTRACT: The present study used nanofluid as the working medium for a disk-shaped miniature heat pipe (DMHP). The nanofluid is a suspension with gold nanoparticles of an average diameter of 17 nm in an aqueous solution. An experimental system was set up to measure the thermal resistance of the disk-shaped miniature heat pipe (DMHP) with both nanofluid and DI-water A mounting base is designed and integrated with the DMHP as a heat spreader for a laser diode TO can package. The present mounting base is made of aluminum (6061 T6). The measured results show that the thermal resistance of the DMHP varies with the charge volume and the type of working medium. At the same charge volume, a significant reduction in the thermal resistance of the DMHP can be found if nanofluid is used instead of DI-water.