This article details the mathematical modeling of a heat sink employing sinusoidal microchannels, embedded with pin-fins, for purposes of liquid cooling of microelectronic chips. The performance of the heat sink is quantified in terms of thermal resistance and pumping power. Studies are done for Reynolds number varying from 250 to 1500. The thermal resistance decreases with increase in Reynolds number while the pumping power increases with increase in Reynolds number. The thermal resistance of the heat sinks with sinusoidal microchannel embedded with pin-fins is much smaller than that of heat sinks with straight microchannels as well as sinusoidal microchannels; however, the pumping power of the former is higher than the other two microchannels. For the cases studied, the reduction in thermal resistance of sinusoidal microchannels embedded with pin fins varied from 21% to 57% compared with that of straight microchannels. Studies revealed that changes in the diameter of pin fin and amplitude of sinusoidal microchannel have noticeable influence on thermal resistance at low Reynolds number but with increase in Reynolds number, the influence of diameter on thermal resistance waned. On the other hand, increase in diameter of the pin fin as well as increase in the amplitude and frequency of the sinusoidal microchannel increased the pumping power for all Reynolds number.