Chitin nano-fibrils, obtained by waste sea food (for example exoskeletons of crustaceous), are available as water diluted nano-suspensions. Hence, their dispersion at the nanoscale in a molten polyester matrix is considered an issue, because diluted liquids cannot be usually added easily in most common extruders. In the present paper the use of poly(ethylene glycol) (PEG) of different molecular weight was investigated to prepare solid pre-composites useful to disperse chitin nanofibrils in poly(lactic acid) (PLA) by extrusion. The tensile properties of injection moulded specimens were determined and insights were also provided regarding the thermal characteristics of chitin nanofibril-reinforced nanocomposites. This study allowed the identification of a process leading to transparent PLA-based nanocomposites suitable to be exploited in packaging and personal care applications, where the intrinsic anti-microbial and tissue regenerative properties of chitin nanofibrils can be greatly useful.