Present paper reports the thermal performance of various phase change material (PCM)-based heat sinks during melting process for cooling of portable electronic devices through experimental investigations. Heat sink configurations include unfinned with pure PCM, finned with pure PCM, unfinned with metallic foam (MF)-PCM composite, and finned with MF-PCM composite. Paraffin wax is used as PCM, and tests have been carried out for various input heat flux values (1.3, 2.0, and 2.7 kW/m(2)) at different volume fractions of PCM (0, 0.50, 0.86, and 1). The effect of various parameters such as PCM volume fraction, heat sink type, and heat flux on the stretching of operating time to achieve a set point temperature (SPT) is studied. Results obtained from the current experimental investigation are compared with the existing test results. Also, unfinned heat sink without and with PCM is used for baseline comparison. The evolution and propagation of melt front inside the heat sink are studied through photographic observation. The enhancement in operating time is found to vary with the SPT and heat flux values. MF-PCM-based heat sinks are more advantageous for higher value of input heat flux (2.0 and 2.7 kW/m(2)). For q('') = 1.3 and 2.0 kW/m(2), four-finned MF-PCM-based heat sink exhibits better performance; while three-finned MF-PCM-based heat sink shows best performance at q('') = 2.7 kW/m(2). The highest enhancement ratio of similar to 2.97 is obtained at 1.3 and 2.7 kW/m(2) for four-finned MF-PCM heat sink and three-finned MF-PCM heat sink, respectively. Also, three-finned heat sink provides higher heat transfer rate and highest thermal conductance at q('') = 2.7 kW/m(2).