The present numerical investigation carried out to obtain the dimensions and parameters for thermal performance optimization of miniature heat sink devices using hybrid nanofluid. Microchannels and minichannels of the surface area of 1x1cm2 and 4x4cm2 were optimized. Water and 1% vol. fraction of Al2O3-MWCNT (50:50)/water hybrid nanofluid was used as coolants. In this study, the heat sinks are thermally optimized on a numerical basis by using basic governing equations, applying boundary conditions and assumptions, and carrying out the optimization scheme. Also, the effect of pressure drop with friction factor, Nusselt number, heat transfer coefficient, and fin efficiency of channel walls on Reynolds number are studied, and comparative analysis is accomplished. Results revealed that a heat sink with lower total thermal resistance would consume more pumping power. However, the thermal performance of the coolant is improved by hybrid nanofluids with a marginal rise in the pumping power