Solar photovoltaic panels can receive only eighty percent of total incident solar radiation. A small amount of incident energy is transformed into electrical energy based on the efficiency of the photovoltaic (PV) cell. The remaining energy leads to an increase in photovoltaic cell operating temperature which affects its life and power output. Cooling of PV panel is the best way to improve the efficiency either by passive or active cooling methods. PV cooling by Phase change materials (PCM) is the best effective technique. Paraffin wax is a non toxic material having high latent heat of fusion used for many thermal applications. In this study, paraffin wax is taken as phase change material in aluminum heat sink with fins. Using DSC, the melting point of paraffin wax is analysed. The flat plate heater is used instead of solar PV panel. Different wattages are used for the experiments. Different inclinations such as horizontal (00 ), vertical (900 ) and intermediate (450 ) were taken in to consideration. The melting starts at 50oC and complete melting occurs at a temperature around 60oC for the paraffin based heat sink. The heat sink surface temperatures, fin temperatures and PCM temperatures are measured. The transient temperature distribution of heat sink, PCM is analysed at different wattage inputs. The total thermal performance of this paraffin PCM based heat sink was analysed experimentally. This infers that the cooling of high temperature of PV panels can be done by using paraffin based PCM to increase the efficiency and life of the panels.