In this paper, the hydrodynamic and thermal performance of a miniature plate pin-finned heat sink is investigated experimentally by utilizing two widely used nanofluids, Al2O3–water and TiO2–water. The heat sink base plate, which is used in the cooling process of electronic devices, has the dimensions of 42 mm (L) × 42 mm (W) × 14 mm (H) and is made of aluminum and placed in a plexiglass case which is isolated from the environment using an insulator foam. The thermal performance of the heat sink is investigated by passing the nanofluid at constant inlet temperature while applying a constant heat flux of 124.8 kW/m2 to the bottom surface of the heat sink. The nanofluids are prepared in volume concentrations of 0.5, 1, 1.5, and 2% and their performances are measured considering water as the base fluid. Measuring the pressure difference between the entrance and exit of the heat sink made it possible to study the hydrodynamic performance of the heat sink. Although the measurements showed 15% and 30% increase in the pumping power for the volume concentration of 2% of Al2O3–water and TiO2–water nanofluids, respectively, the average heat transfer coefficients increased by 16% and 14% and the thermal resistance decreased by 17% and 14% for each nanofluid.