As mentioned above, many researchers have reported that the nanofluid-cooled heat Amrubicin with microchannel and pin fin structures show significant heat transfer enhancement with small or no penalty drop in pressure. Even though there was significant research on the thermal and flow characteristics of nanofluid-cooled heat sinks, most researches have been restricted to the numerical approach. For experimental approach, few articles was conducted. So far, the present study aims to evaluate the thermal and hydraulic performance of two different types of nanofluid flowing through a heat sink with miniature circular pin fin structure and having small flow channel, experimentally. SiO2 and ZnO nanoparticles with volume concentration of 0.2, 0.4 and 0.6 vol.% are used as coolant and then compared with the data for water. Heat sink made from aluminum material with a mean hydraulic diameter of 1.2 mm (for each flow channel) and heat transfer area of 1430 mm2 is used as the test section. The effects of particle type, particle concentration, and flow rate on the thermal and hydraulic performances are presented. Moreover, new heat transfer and pressure drop correlations are proposed in a more convenient form for calculating the Nusselt number and the pressure drop of nanofluids flow in heat sinks with pin fin structure.