The melting and crystallization behavior of the matrix polymer and the composites were studied using a TA Instruments 2920 Modulated Differential Scanning Calo- rimeter (DSC) equipped with a cooling attachment, under a nitrogen atmosphere. The data were collected by heating the composite specimen from 25 to 200 °C at a constant heating rate of 5 °C/min. A sample weight of approxi- mately 10 mg was used. The samples were sealed in alumi- num pans and the sealed samples were placed on a heating surface in the furnace along with an empty reference alumi- num pan. The heat flow and energy changes in and out of the samples in the sealed aluminum pans were recorded with reference to an empty aluminum pan. The melting temperature was obtained from the peak in the heating curve. The determination of melting temperature of the PLA-RNCF system helped to evaluate the processing tem- peratures that were needed on the extruder when natural fiber was added to the system to fabricate the composite.