Biodegradable poly lactide (PLA)/ graphene nanoplatelet (GNP) nanocomposites were prepared by melt intercalation. Morphological studies were carried out via scanning electron microscopy and X-ray diffraction. Results showed good dispersion of GNPs in PLA at low filler concentrations. Semicrystalline structure of PLA was found to change under the effect of GNP incorporation which was also confirmed by differential scanning calorimetry measurements. Dynamic viscoelastic properties of the nanocomposites exhibited significant enhancement with increasing GNP loading. In particular, storage modulus showed less frequency dependency in the low frequency region leading to a percolation threshold of between 6 and 9wt% at 180 °C. Increasing the temperature of measurements showed that nanocomposites with high GNP loadings not only did not obey the time-temperature superposition but exhibited an unusual behaviour. In the low frequency region, viscoelastic properties of the nanocomposites increased with increasing temperature in contrast to the ideal melt behaviour. This was attributed to the changes in the different interactions present in the system with increasing the temperature resulting in occurrence of physical gelation at lower GNP concentrations.