The effect of the Pin-fin shapes on the overall performance of the micro Pin-fin heat sink with staggered arrangement is studied in this paper. Six different shapes of micro Pin-fins, square, rectangle, circle, rhombus, triangle and ellipse are subjected to study in this paper. The optimization processes are carried out using computer simulations performed using COVENTORWARE™. The study is carried out over a range of Reynolds number ranging from 50 to 500 and a figure of merit term (FOM) consisting of both the thermal resistance and the pumping power is developed for the overall performance evaluation of different models. A weighted average scheme is used for developing the FOM term. The results of the study revealed that at low values of Reynolds numbers (Re<200) circle has the best performance and at high values of Re (Re>200) rectangle showed the best performance.